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Francesca BOSELLINI

Professore Associato
Dipartimento di Scienze Chimiche e Geologiche - Sede Dipartimento di Scienze Chimiche e Geologiche

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Pubblicazioni

2023 - High-diversity larger foraminiferal assemblages calibrated with calcareous nannoplankton biozones in the aftermath of EECO (Collio, Friuli-Venezia Giulia, northeastern Italy) [Articolo su rivista]
Benedetti, A.; Papazzoni, C. A.; Bosellini, F.; Giusberti, L.; Fornaciari, E.
abstract

The Eocene of Collio (easternmost Friuli-Venezia Giulia, northeastern Italy) contains rich larger foraminiferal assemblages mainly dominated by nummulitids of genera Nummulites and Assilina. Herein, we document, by typological and biometric approaches, upper Ypresian to lower Lutetian taxa, dated by an integrated biostratigraphy combining the Shallow Benthic Zones (SBZ) with the nanno- fossil biozones. A total of seven species of Alveolina, 12 species of Assilina and 33 of Nummulites are described (in Appendix A), some of them left in open nomenclature. The larger foraminiferal assemblages indicate that all the collected samples are assignable to SBZ12 and SBZ13 and their high diversity suggests high resilience of these shallow-water taxa after the Early Eocene Climate Optimum warming event. The occurrence of the calcareous nannofossil Blackites inflatus together with Alveolina violae Nummulites friulanus, N. campesinus, N. quasilaevigatus, Assilina maior maior and A. cuvillieri, typical SBZ12 markers, suggests that SBZ12 extends at least to the basal Lutetian, thus the SBZ12/13 boundary occurs in the lowermost Lutetian instead of at the Ypresian/Lutetian transition.

2022 - A coral hotspot from a hot past: The EECO and post-EECO rich reef coral fauna from Friuli (Eocene, NE Italy) [Articolo su rivista]
Bosellini, Francesca R.; Benedetti, Andrea; Budd, Ann F.; Papazzoni, Cesare A.
abstract

The early Paleogene “greenhouse” is the warmest geological period of the Cenozoic and a suitable source to unlock crucial information for better understanding how ecosystems such as coral reefs reacted to a climate much warmer than the present. Herein, we analyse in detail the rich museum coral collections from Friuli region (NE Italy) focusing only on the so-called reef corals, mostly colonial, and on those localities for which the age constraints are well-defined. We grouped the localities into four time-intervals within the Ypresian-Lutetian and thus within EECO (Early Eocene Climatic Optimum) and post-EECO phase, in order to assess the main changes in the following traits: 1) richness and relative abundance at the generic and species level; 2) relative abundance of growth forms; 3) colony size. By systematic revision we recognized a total of 37 genera and 103 species. During the EECO interval (late Ypresian or Cuisian), the diversity at both genus and species level was relatively low (21 genera, 37 species). An abrupt increase is then recorded in the post-EECO 1 interval (latest Ypresian), whereas a peak is reached in the earliest Lutetian (post-EECO 2) (35 genera, 90 species). These results undoubtedly show that a coral hotspot occurred in the region during the late Ypresian-early Lutetian time and highlight that corals of Friuli reacted positively immediately after the warming event of the EECO. This coral hotspot was the most diverse at global scale during the Ypresian and formed in a deltaic depositional setting, most probably in mesophotic conditions as suggested by the dominant growth forms, where rapid sediment accumulation, enhanced nutrient delivery and stressful climatic conditions reduced frame-building capacity. We finally document that corals were resilient to climate stressors and recovered before reefs which, in contrast, required much more time to achieve their buildup potential.

2021 - High coral diversity is coupled with reef-building capacity during the Late Oligocene Warming Event (Castro Limestone, Salento Peninsula, S Italy) [Articolo su rivista]
Bosellini, Francesca R.; Vescogni, Alessandro; Budd, Ann F.; Papazzoni, Cesare A.
abstract

The Oligocene, well known as the apex of Cenozoic reef growth, is a crucial period of time to investigate the mutual relationship between coral reef construction and coral diversity and their link with palaeoclimate and palaeoenvironmental changes. Here we provide a complete characterization of the upper Oligocene reef complex of the Castro Limestone (Salento Peninsula, S Italy), which is one of the best-preserved Oligocene coral reefs of the Mediterranean region. By combining facies analysis with the first detailed characterization of its coral fauna, we show that the Castro Limestone has both a rich scleractinian coral fauna (25 genera and 41 species) and a large reef volume, and it represents a luxuriant fringing reef formed within the euphotic zone in clear water conditions facing the open sea. The coral fauna differs both in its composition and in its proportions among reef palaeoenvironments, ranging from the shallow back reef to the fore reef slope, and its stratigraphic and palaeogeographic distribution testifies to the persistence of a cosmopolitan Tethyan fauna in Oligocene time, with the Mediterranean and Indo-Pacific provinces being more closely connected than the Mediterranean and the Caribbean. The age of the Castro Limestone is here reassigned to the middle-late Chattian, which coincides with the Late Oligocene Warming Event (LOWE) when atmospheric CO2 values declined. We suggest that the strong reef-building capacity of the Castro Limestone, coupled with high coral diversity, was not hampered by warming conditions but most probably promoted by the reduced pCO2 and a suitable local/regional physiographic setting.

2020 - A first glimpse on the taphonomy and sedimentary environment of the Eocene siliceous sponges from Chiampo, Lessini Mts, NE Italy [Articolo su rivista]
Frisone, Viviana; Preto, Nereo; Pisera, Andrzej; Agnini, Claudia; Giusberti, Luca; Papazzoni, Cesare Andrea; De Angeli, Antonio; Beschin, Claudio; Mietto, Paolo; Quaggiott, Ermanno; Monaco, Paolo; Dominici, Stefano; Kiessling, Wolfgang; Luciani, Valeria; Roux, Michel; Bosellini, Francesca R.
abstract

A diverse assemblage of bodily preserved sponges has been recovered from a lower Lutetian tuffite horizon in the Chiampo Valley, Lessini Mountains, Italy. The sponge assemblage is dominated by hexactinellids and lithistids. Using uniformitarian criteria, the composition of the assemblage suggests a water depth greater than 200 m. Sponges are often preserved in growth position including sponge clusters. Taphonomic processes facilitating sponge preservation include rapid burial of a living sponge community and early diagenetic calcification. Different modes of attachment suggest heterogeneous substrate conditions. The associated fauna, such as abundant pteropods in the matrix and in-situ preserved crinoids, confirms a rather deep-water environment. However, there are also common benthic elements of shallow-water origin. Although some of these elements show signs of transport, others, such as decapod crustaceans, do not. Moreover, trace fossils indicate high-energy environments. To reconcile these observations, we propose rapid, tectonically triggered sea-level changes.

2020 - Capitolo 6 - Cnidaria [Capitolo/Saggio]
Bosellini, F.
abstract

2020 - Exceptional development of dissepimental coenosteum in the new Eocene scleractinian coral genus Nancygyra (Ypresian, Monte Postale, NE Italy) [Articolo su rivista]
Bosellini, Francesca R.; Stolarski, Jarosław; Papazzoni, Cesare Andrea; Vescogni, Alessandro
abstract

In colonial corals, the polyps are interconnected with a common tissue called coenosarc. Polyps and coenosarc secrete distinct skeletal structures: corallites and coenosteum, respectively. Ratio of corallite to coenosteum development may vary resulting in two extreme architectural patterns of coral colonies: corallite-dominated (e.g., cerioid) and coenosteum-dominated (e.g., aphroid) colonies. A large suite of examples of these patterns can be identified among extant and fossil corals, including Paleozoic rugosan corals. Herein we describe the new early Eocene colonial scleractinian coral genus Nancygyra that forms exceptional coenosteum-dominated colonies. The colonies were found in Ypresian limestones at Monte Postale (Lessini Mountains, Veneto, NE Italy), very close to the Pesciara di Bolca Fossil-Lagerstätte, where coralgal buildups have been recently recognised and described. The corallum is massive and consists of corallites of variable size (typically few millimeters in lesser calicular diameter) dispersed and protruding from a very extensive and dense dissepimental coenosteum. The coenosteum forms ca. 60-80% of the corallum volume and is made of vesicular convex dissepiments. The new coral is tentatively assigned to Euphylliidae (known in the fossil record since the Paleocene) whose modern representatives develop similar extensive coenosteum with sticking-out corallites (Galaxea) and form coralla with well-developed walls and thickened axial margins of septa (Euphyllia). Among stratigraphically older scleractinian corals, similar extent of dissepimental coenosteum development is shown by some Mesozoic amphiastreids and rhipidogyriids.

2020 - Paleo-archives of Cnidaria and Porifera in space and time: Proceedings of the 13th international symposium on fossil cnidaria and porifera [Articolo su rivista]
Bosellini, Francesca R.; Papazzoni, Cesare Andrea; Vescogni, Alessandro
abstract

2020 - Revisiting reef models in the Oligocene of northern Italy (Venetian Southern Alps) [Articolo su rivista]
Bosellini, Francesca R.; Vescogni, Alessandro; Kiessling, Wolfgang; Zoboli, Alessandro; Di Giuseppe, Dario; Papazzoni, Cesare Andrea
abstract

The lower Oligocene coral communities and reefs exposed in the Lessini Shelf of northern Italy may record one of the oldest well-developed barrier reef/lagoon systems of the Cenozoic. However, the rimmed-shelf interpretation has been repeatedly challenged in favour of a ramp model with scattered corals. Based upon a re-analysis of selected localities in the Lessini Shelf, we here provide support for the barrier reef model based on four key observations: 1) systematic changes of coral growth-forms from branching in the proximal areas to massive at the platform margin; 2) a progressive increase of the hydrodynamic energy from the proximal belt towards the more distal environments in the Berici Hills; 3) the occurrence of shallow-water, euphotic conditions throughout the whole depositional system; and 4) the presence of restricted circulation in the proximal environments during sea-level lowstands, with lack of coral colonies. These features, together with the evidence of coral frameworks located on the southeastern edge of the Lessini Shelf, substantiate the occurrence of a reef-rimmed margin. The reefal rim acted as an efficient barrier, with the formation of a landward, wide lagoon protected from the action of waves and currents.

2019 - Correction to: High coral reef connectivity across the Indian Ocean is revealed 6–7 Ma ago by a turbid-water scleractinian assemblage from Tanzania (Eastern Africa) (Coral Reefs, (2019), 38, 5, (1023-1037), 10.1007/s00338-019-01830-8) [Articolo su rivista]
Reuter, M.; Bosellini, F. R.; Budd, A. F.; Coric, S.; Piller, W. E.; Harzhauser, M.
abstract

This erratum is published because vendor overlooked corrections related to Table 2 during proofing.

2019 - High coral reef connectivity across the Indian Ocean is revealed 6–7 Ma ago by a turbid-water scleractinian assemblage from Tanzania (Eastern Africa) [Articolo su rivista]
Reuter, M.; Bosellini, F. R.; Budd, A. F.; Ćorić, S.; Piller, W. E.; Harzhauser, M.
abstract

he present centre of coral diversity in the Western Indian Ocean is defined by the northern Mozambique Channel with an extension northward to Mafia Island in Tanzania (Eastern Africa). The geological and evolutionary history of this hotspot of marine biodiversity remains so far completely obscure, because Cenozoic fossil reef communities of this area are not well known. This study presents a new fossil scleractinian fauna from the Mikindani Formation in southern Tanzania. It comprises 16 symbiotic coral taxa of which nine could be identified to the species and five to the genus level. Coral habitat consisted of low-relief biostromes that developed in shallow water at the front of the Rovuma Delta under conditions of variable sediment input. The biostromes are dated to be Messinian based on associated calcareous nannoplankton and planktic foraminifers. The studied coral assemblage shows close affinities with the Recent Western Indian Ocean biogeographic province and Central Indo-West Pacific biogeographic region as well as with the Miocene of Indonesia. Faunistic relations with the Oligocene-early Miocene of Somalia and Iran do not exist. The patterns of species distribution document a major palaeobiogeographic change in the Indian Ocean that correlates with the onset of the Miocene Indian Ocean Equatorial Jet during the middle Miocene. The clear Indonesian affinity of the Messinian coral fauna from southern Tanzania implies that this westerly oceanic surface current provided high biogeographic connectivity across the Indian Ocean during the late Miocene. Today, the coastal waters of Indonesia are located in the Coral Triangle. Diversification of this global epicentre of marine biodiversity started in the early Miocene and it was established already during the middle Miocene. Our results indicate that the East African hotspot of coral biodiversity originated as an offshoot of the Coral Triangle in the middle to late Miocene.

2019 - Impact of ocean acidification on crystallographic vital effect of the coral skeleton [Articolo su rivista]
Coronado, Ismael; Fine, Maoz; Bosellini, Francesca; Stolarski, Jaroslaw
abstract

Distinguishing between environmental and species-specific physiological signals, recorded in coral skeletons, is one of the fundamental challenges in their reliable use as (paleo)climate proxies. To date, characteristic biological bias in skeleton-recorded environmental signatures (vital effect) was shown in shifts in geochemical signatures. Herein, for the first time, we have assessed crystallographic parameters of bio-aragonite to study the response of the reefbuilding coral Stylophora pistillata to experimental seawater acidification (pH 8.2, 7.6 and 7.3). Skeletons formed under high pCO2 conditions show systematic crystallographic changes such as better constrained crystal orientation and anisotropic distortions of bio-aragonite lattice parameters due to increased amount of intracrystalline organic matrix and water content. These variations in crystallographic features that seem to reflect physiological adjustments of biomineralizing organisms to environmental change, are herein called crystallographic vital effect (CVE). CVE may register those changes in the biomineralization process that may not yet be perceived at the macromorphological skeletal level. https://doi.org/10.1038/s41467-019-10833-6 OPEN 1

2018 - New paleoenvironmental insights on the Miocene condensed phosphatic layer of Salento (southern Italy) unlocked by the coral‑mollusc fossil archive [Articolo su rivista]
Vescogni, Alessandro; Vertino, Agostina; Bosellini, Francesca R.; Harzhauser, Mathias; Mandic, Oleg
abstract

From the Late Oligocene to the Late Miocene, the central Mediterranean area was characterized by the extensive deposition of phosphate-rich sediments. They are usually represented by 10 to 20-cm-thick hardgrounds made of phosphatic and glauconitic sediments containing a rich macrofossil association. This study represents the first thorough investigation of the biotic assemblage of Mediterranean phosphorites aimed at collecting new information on the environmental factors controlling their deposition. The Serravallian/Tortonian phosphatic deposits of the Salento Peninsula (“Aturia level”) have been selected for the abundance of fossil remains and special attention is given to the coral–mollusc association. Two different facies have been recognized: a basal coral rudstone that includes most of the macrofossils, superimposed by a detrital rudstone made of thin layers mainly composed of phosphatic fragments. These two facies are separated by a phosphatic crust several millimeters in thickness. The coral assemblage contains at least 17 azooxanthellate taxa belonging to four families, while the molluscs are represented by a rich gastropod fauna (26 species), associated with bivalves (18 species) and cephalopods (two species). Four distinct depositional phases have been recognized, with the coral rudstone representing the key-facies to reconstruct the onset of the “Aturia level” and the original environment of its fossil content. The composition of the coral–mollusc association has been reliably compared with present-day analog taxa, suggesting the occurrence of a heterogeneous seafloor formed by rocky substrates and accumulations of soft sediment, at around 100–350-m water depth, and under the influence of moderate-to-strong bottom currents rich in nutrients and resuspended organic matter.

2016 - A unique coral biomineralization pattern has resisted 40 million years of major ocean chemistry change [Articolo su rivista]
Stolarski, J.; Bosellini, Francesca; Wallace, C. C.; Gothmann, A.; Mazur, M.; Domart Coulon, I.; Gutner Hoch, E.; Neuser, R. D.; Levy, O.; Shemesh, A.; M. e. i. b. o. m., A.
abstract

Today coral reefs are threatened by changes to seawater conditions associated with rapid anthropogenic global climate change. Yet, since the Cenozoic, these organisms have experienced major fluctuations in atmospheric CO2 levels (from greenhouse conditions of high pCO2 in the Eocene to low pCO2 ice-house conditions in the Oligocene-Miocene) and a dramatically changing ocean Mg/Ca ratio. Here we show that the most diverse, widespread, and abundant reef-building coral genus Acropora (20 morphological groups and 150 living species) has not only survived these environmental changes, but has maintained its distinct skeletal biomineralization pattern for at least 40 My: Well-preserved fossil Acropora skeletons from the Eocene, Oligocene, and Miocene show ultra-structures indistinguishable from those of extant representatives of the genus and their aragonitic skeleton Mg/Ca ratios trace the inferred ocean Mg/Ca ratio precisely since the Eocene. Therefore, among marine biogenic carbonate fossils, well-preserved acroporid skeletons represent material with very high potential for reconstruction of ancient ocean chemistry.

2016 - Are coral reefs victims of their own success? [Articolo su rivista]
Renema, W.; Pandolfi, J. M.; Kiessling, W.; Bosellini, Francesca; Klaus, J. S.; Korpanty, C.; Rosen, B. R.; Santodomingo, N.; Wallace, C. C; Webster, J. M.; Johnson, K. G.
abstract

As one of the most prolific and widespread reef builders, the staghorn coral Acropora holds a disproportionately large role in how coral reefs will respond to accelerating anthropogenic change. We show that although Acropora has a diverse history extended over the past 50 million years, it was not a dominant reef builder until the onset of high-amplitude glacioeustatic sea-level fluctuations 1.8 million years ago. High growth rates and propagation by fragmentation have favored staghorn corals since this time. In contrast, staghorn corals are among the most vulnerable corals to anthropogenic stressors, with marked global loss of abundance worldwide. The continued decline in staghorn coral abundance and the mounting challenges from both local stress and climate change will limit the coral reefs’ ability to provide ecosystem services.

2016 - Coral assemblages and bioconstructions adapted to the depositional dynamics of a mixed carbonate-siliciclastic setting: the case study of the Burdigalian Bonifacio Basin (South Corsica) [Articolo su rivista]
Brandano, M.; Bosellini, Francesca; Mazzucchi, A.; Tomassetti, L.
abstract

Coral bioconstructions associated with mixed carbonate-siliciclastic settings are known to be strongly controlled by coastal morphology and paleotopography. A striking example is represented by the different types of coral bioconstructions and coral-rich deposits of the Cala di Labra Formation deposited in the coastal environment of the Bonifacio Basin (Corsica, France) during the Early Miocene. Detailed mapping on photomosaics allowed accurate documentation of the internal organization of coral deposits as well as lateral and vertical facies relationships. Four types of coral bioconstructions (CB) and one reworked coral deposits (RCD) have been recognized. The CB are represented by sigmoidal cluster reefs, coral carpets and skeletal conglomerates rich in corals. The RCD occurs in lens-shaped bodies intercalated within clinoforms composed of bioclastic loatstones and coarse packstones. The investigated bioconstructions can be contextualised in a coastal environment. In the upper shoreface corals developed in association with the oyster Hyotissa, above bioclastic conglomerates sourced by ephemeral streams and erosion of the granitic coastline. In the lower shoreface corals formed sigmoidal bioconstructions interpreted as cluster reefs, whereas coral carpets developed during a relative sea-level rise related to the middle Burdigalian transgressive phase. The reworked coral deposits can be interpreted as lobe-shaped deposits of coarse-grained bioclastic submarine fans formed at the base of the depositional slope of an infralittoral prograding wedge system.

2016 - Coralgal buildups associated with the Bolca Fossil-Lagerstätten: new evidence from the Ypresian of Monte Postale (NE Italy) [Articolo su rivista]
Vescogni, Alessandro; Bosellini, Francesca; Papazzoni, Cesare Andrea; Giusberti, L.; Roghi, G.; Fornaciari, E.; Dominici, S.; Zorzin, R.
abstract

The Monte Postale and Pesciara di Bolca sites are well-known Eocene Fossil-Lagerstätten. The origin of these deposits has been previously related to a lagoon environment, protected from the open sea by a barrier formed by some kind of reef. However, no detailed description of a bioconstructed system has ever been reported in the area. This study provides the first detailed characterization of the upper Ypresian Monte Postale reef, made of in situ corals, calcareous algae, and encrusting foraminifera. Three main facies associations have been recognized: (1) a coralgal rim, roughly E/W oriented, (2) lagoon deposits in the south and (3) fore-reef sediments towards the north. The coralgal rim is represented by a wave-resistant framework made of heavily calcified organisms associated to Alveolina accumulations; the adaptation of most of these organisms to the euphotic zone promoted their growth in proximity to the sea level, allowing this structure to act as an effective barrier. In particular, during relative sea-level lowstands or highstands, the coralgal rim could have limited the water exchange between the lagoon and the open sea, reducing the oxygenation in the lagoon and allowing the formation of the Fossil-Lagerstätten. During relative sea-level transgressions, the water could have risen well above the margin, establishing normal oxygenation and hampering the fossils’ preservation. The Monte Postale succession represents one of the few examples of lower Eocene bioconstructions. The description of this biotic assemblage provides new data for the characterization of reef communities during a crucial climatic phase, near the end of the early Eocene climatic optimum global warming.

2016 - Fossili cenozoici della Valsugana. Catalogo della "Collezione Boschele", parte II [Articolo su rivista]
Boschele, S.; Gatto, R.; Beranrdi, M.; Bosellini, Francesca; Avanzini, M.
abstract

Cenozoic fossils from Valsugana. Catalogue of the “Boschele Collection”, part II – This second contribution to the description of the Boschele palaeontological collec- tion present a systematic study of ~ 250 specimens, mainly marine invertebrates, found in several stratigraphical levels dating to the early Oligocene. Fossil localities, all located nearby Borgo Valsugana (East Trentino Province), testify to the development of an articulated palaeogeography in the northern sector of the Lessini Shelf. In this context, the corals of the Maso creek described in this catalogue and never documented before, constitute the northernmost discovery so far in the Lessini Platform coral fauna and indicate an environmental evolution that allowed the growth of small but flourishing bioconstructions even in the vicinity of the emergent land. The depositional environment was therefore dominated by terrigenous sedimentation that originated conditions of rather turbid waters.

2016 - Fossili cenozoici della Valsugana. Catalogo della "Collezione Boschele", parte III [Articolo su rivista]
Boschele, S.; Gatto, R.; Bernardi, M.; Tattesi, B.; Bosellini, Francesca; Avanzini, M.
abstract

Cenozoic fossils from Valsugana. Catalogue of the Boschele collection, part III – This third contribution to the description of the “Boschele palaeontological Collection” present a systematic study of ~300 specimens, mainly marine invertebrates, found in several stratigraphical levels dating to the early Oligocene. In this contribution we describe the first vertebrate remains found in Paleogene sediments of Valsugana (Trento Province sector). They represent the highest trophic levels of the shallow sea that during the Rupelian developed in the northernmost sector of the Lessini Shelf. The vertebrate fauna includes dugongids and chelonians (represented by numerous skeletal remains), diodontids, sparids and cartilaginous fish (all documented by the exclusive presence of isolated teeth). The skeletal remains, disarticulated and severely abraded are interpreted as indicative of high-energy phases, which could, however, be interrupted by moments of stasis. During such events skeletal remains accumulated on the seafloor and underwent predation by invertebrates as documented by the presence of feeding traces, in particular on dugongid remains.

2016 - Revision of Oligocene Mediterranean meandroid corals in the scleractinian families Mussidae, Merulinidae, and Lobophylliidae [Articolo su rivista]
Budd, A. F.; Bosellini, Francesca
abstract

Traditional morphology-based systematics indicates close evolutionary relationships between Caribbean and Indo-Pacific ‘faviid’ and ‘mussid’ reef corals. However, molecular phylogenies reveal three distinct family-level clades, which diverged by middle Eocene time: (1) Caribbean faviids + mussids; (2) Indo-Pacific faviids; and (3) Indo-Pacific mussids. During the early Cenozoic, members of these clades also occurred in a third geographical region, the Mediterranean, but became extinct in that region during the Miocene, as the Tethys broke up. We perform morphological phylogenetic analyses including Caribbean, Indo-Pacific and Mediterranean Oligocene and Recent taxa to reconstruct the pattern of divergence between the three regions, and examine how it was related to biogeography. First, fossil specimens were selected from museum collections, and a total of 13 species (three of which are new) were distinguished using nine morphological features. These 13 species were then added to a dataset with taxa consisting of 62 Recent plus one additional extinct species, and with 50 characters. In addition to traditional macromorphology, the characters include new micromorphological and microstructural features observed using electron microscopy and transverse thin sections. Phylogenetic analysis was performed on the dataset using parsimony. The results show that, contrary to traditional systematics, 11 of the 13 Mediterranean extinct coral species group more closely with Indo-Pacific taxa than they do with Caribbean taxa. Recent Caribbean taxa and Indo-Pacific ‘mussids’ form distinct clades; but Indo-Pacific ‘faviids’ form four poorly resolved subclades basal to the Caribbean clade. These results suggest that Mediterranean meandroid corals belong to a cosmopolitan pantropical fauna, from which modern Caribbean meandroid corals diverged as the Caribbean became isolated. Phylogenetic analyses including fossils have higher resolution than analyses including only modern corals. The systematics of the 13 extinct species are formally revised. Two new species – Variabilifavia ausuganensis sp. nov. and Echinophyllia sassellensis sp. nov. – and one new genus – Paraleptoria gen. nov. – are named, and one undescribed species is left in open nomenclature. Two previously synonymized genera are resurrected.

2015 - Acropora (Scleractinia) from the Oligocene and Miocene of Europe: species longevity, origination and turnover following the Eocene–Oligocene transition [Articolo su rivista]
Wallace, C. C.; Bosellini, Francesca
abstract

Four new species and new records for six species of the highly successful reef-building coral genus Acropora are described from Oligocene and Early Miocene (Rupelian to Burdigalian) localities in Europe. Acropora slovenica sp. nov. is described from Slovenia (Gornji Grad beds); A. piedmontensis sp. nov. and A. macrocalyx sp. nov. from the Torino Hills (Piedmont), and A. salentina sp. nov. from the Salento Peninsula (Apulia) of Italy. The remaining six species have an Eocene lineage. From south-west France, A. anglica and A. bartonensis, previously known from England (Priabonian and Bartonian), are recorded: A. anglica in Oligocene (Chattian) and both in Miocene (Aquitanian) deposits, indicating their persistence in the western Tethys for up to 17 and 20 million years respectively. Also recorded from Aquitaine is A. wilsonae (type locality Eocene Paris Basin), indicating persistence in western France for up to 28 million years. Italian material includes A. proteacea, also known from the Lower Bartonian of France and A. lavandulina, already known from Italy and the Eocene of France. From Slovenia (Oligocene, Rupelian), A. haidingeri is recorded, including from the type locality. The species are interpreted as representing seven extant species groups previously documented from the Eocene of Europe and the first records for two further extant groups. These results complement a previous finding of Eocene diversification of Acropora into the beginnings of up to 10 of the 20 recognized modern species groups in England and France. They indicate that the longevity of some Eocene taxa was extended into the Oligocene to Early Miocene of Europe and allowed some turnover, probably associated with changes in configuration of the western Tethys Sea. This information is important for interpreting molecular phylogenies and the evolution of modern Acropora diversity, by providing extended stratigraphical ranges for species groups with Eocene origins and dates of origination for two groups previously unrecorded in the early fossil record.

2015 - La sezione del Monte Postale (Eocene dei Monti Lessini, Veneto): associazioni fossili e ricostruzione paleoambientale. [Abstract in Atti di Convegno]
Papazzoni, Cesare Andrea; Vescogni, Alessandro; Bosellini, Francesca; Giusberti, Luca; Fornaciari, Eliana; Roghi, Guido; Dominici, Stefano
abstract

2015 - Structure, morphogenesis, and evolution of fibrous skeleton in acroporiid scleractinian corals [Abstract in Atti di Convegno]
Stolarski, J.; Bosellini, Francesca; Wallace, C. C.; Neusser, R. D.; Meibom, A.
abstract

Exceptionally well-preserved fossil representatives of Acropora from the Eocene, Oligocene, and Miocene shallow-water deposits exhibit remarkable evolutionary stability of biomineralization patterns despite major geochemical fluctuations: including the transition from greenhouse conditions (Eocene) to icehouse conditions (Oligocene) and from low Mg/Ca "calcitic seas" during the Eocene through rapidly increasing Mg/Ca "aragonite seas" since the Oligocene. Implications for scleractinian coral biomineralization and evolution will be discussed.

2015 - The Middle Eocene Monte Postale succession: a new record of a greenhouse coral reef-building association (Veneto, northern ltaly). [Abstract in Atti di Convegno]
Vescogni, Alessandro; Bosellini, Francesca; Papazzoni, Cesare Andrea; Fornaciari, Eliana; Giusberti, Luca; Roghi, Guido; Dominici, Stefano; Olivieri, Andrea
abstract

2014 - A new Fossil-Lagerstätte from the Lower Eocene of Lessini Mountains (northern Italy): A multidisciplinary approach. [Articolo su rivista]
Giusberti, L.; Bannikov, A.; Boscolo Galazzo, F.; Fornaciari, E.; Frieling, J.; Luciani, V.; Papazzoni, Cesare Andrea; Roghi, G.; Schouten, S.; Sluijs, A.; Bosellini, Francesca; Zorzin, R.
abstract

Hemipelagic dark limestones within calciturbiditic deposits at Monte Solane in the western Lessini Mountains of northern Italy yield a fish fauna dominated by stomiiforms. A minor component of the fossil assemblage is represented by macroalgal non-calcareous flora associated to rarer terrestrial components including few angiosperm leaves and seeds. Micropaleontological (foraminifera, dinoflagellate cysts), sedimentological and geochemical proxies (TEX86) indicate deposition of the fossil-bearing bed in a hypoxic to possibly anoxic, warm, restricted basin. High-precision dating based on rich foraminiferal and calcareous nannoplankton content allows ascribing the site to the upper part of the Ypresian (Early Eocene). The site is slightly older than the Ypresian worldwide-famous shallow-water Bolca Konservat-Lagerstätte located in the same region. Convergent paleoenvironmental clues based on both microfossils and ichthyofauna indicate that the sediments were deposited in the upper bathyal zone, probably between 300 and 600 m. Solane is therefore one of the rare and precious Eocene Lagerstätte to have fossilized in a deep marine setting. The site contains the oldest Cenozoic record of an ichthyofauna dominated by meso-bathypelagic taxa.

2014 - Coral bioconstruction variability in a small basin: the Burdigalian Bonifacio basin (South Corsica). [Articolo su rivista]
A., Mazzucchi; Bosellini, Francesca; L., Tomassetti; M., Brandano
abstract

Coral-rich deposits and coral bioconstructions characterize the mixed carbonate-siliciclastic systems developed in the Bonifacio Basin during the Early Miocene. Accurate mapping on photomosaics allowed to document the internal organization of coral deposits as well as lateral and vertical facies relationships. Thin sections observation contributes to textural characterization and skeletal components identification. Notwithstanding the small size of the basin (4 x 8 km) at least six types of coral bioconstructions and related depositional geometries are developed. 1) Above gently sloping substrate patch reefs occur in a wedge-shaped system. Siliciclastic facies characterizes the nearshore environment and carbonate production dominates the meso-oligophotic zone, where coral build-up passes basinward to the maerl facies. 2) In the pocket beach oysters and domal coral colonies rapidly colonize gravel and boulders of shoreface setting. 3) On rocky shore, coral buildup is organized in a lens-shaped structure showing a core mainly constituted by a relatively dense coral domestone with a moderate increase of platy corals in the upper part. A coral rubble associated with granitic cobbles and pebbles is locally present at the base of the structure. 4) Coral carpets developed in a patchy pattern on coarse skeletal sand of the shoreface environment. 5) Closer to the granitic basement, coral bioconstruction made up of a coral domestone that may developed on coastal conglomerate evolving basinward to a coarse hybrid sandstone with isolated large domal coral colonies. 6) Cross-bedded coral rudstone to floatstone formed at the base of clinoforms representing the failure of patch reefs developed on the shelf break of an infralittoral prograding wedge system. The inherited topography produced by the Hercynian crystalline basement, together with the oceanography and the sedimentary processes acting in this small basin, are responsible for having produced such coral bioconstructions variability.

2014 - First evidence of coral bioconstructions in the Monte Postale succession (Lower Eocene of Lessini Mts., Veneto, northern Italy) [Articolo su rivista]
Papazzoni, Cesare Andrea; Vescogni, Alessandro; Bosellini, Francesca; Giusberti, L.; Roghi, G.; Dominici, S.
abstract

The world-famous Fossil-Lagerstätten of the Bolca area have long been interpreted (e.g., Sorbini, 1972) as deposited in a carbonate platform setting, within an intra-platform depression or basin, protected from the open-marine environment by some kind of threshold (Papazzoni & Trevisani, 2006; Schwark et al., 2009). The presence of corals, both in the Pesciara di Bolca site and in the nearby Monte Postale succession, suggests that the threshold may be formed by some kind of bioconstructed margin. Although the occurrence of a possible “reef” environment has been suggested by the composition of the fish fossil assemblage (Landini & Sorbini, 1996; Belwood, 1996; Bellwood et al., 2014), no direct observation of a preserved coral bioconstruction has ever been reported for the Bolca area. The Monte Postale succession represents the most complete stratigraphic record of the area, tracing the depositional history before and after the deposition of the laminated limestones containing the fish fauna of the Bolca Lagerstätten. Considering that the last detailed study of the area dates from the beginning of the last century (Fabiani, 1914), a new survey was necessary to update the knowledge of both paleoecological and biostratigraphic aspects. During this survey, some massive limestone bodies were observed, and their in situ position within the stratigraphic succession was ascertained. They turned out to be small bioconstructions, a few metres thick, with abundant coral colonies in growth position or preserved as broken rubble. Detailed field mapping and facies analysis of several of these structures allowed the identification of a discontinuous belt along the northern side of the Monte Postale, and to recognize four different facies types: - Facies A: Coral boundstone. It forms the bulk of the massive outcrops (Fig 1a, b). Dominant genera are Goniopora, Stylophora, Actinacis, Goniastrea, Astrocoenia and Astreopora, while Stylocoenia, Siderastrea, Pachygyra and Caulastrea are subordinate. Corals are often encrusted by foraminifera and coralline red algae. A fine-grained micritic wackestone fills the small cavities among the colonies, associated also with a coarser Alveolina packstone. In both cases, fragments of dasycladacean green algae represent one of the most important bioclastic components. - Facies B: Stratified Alveolina grainstone. This facies represents the sediment above and within Facies A (Fig 1a). Associated with the larger forams, coral fragments are also abundant. - Facies C: Well-bedded, fine-grained packstone. These sediments onlap on the south-eastern side of the massive outcrops (Fig. 1b), and mainly contain small fragments of Alveolina and corals. The stratified packstone succession is sometimes interrupted by the presence of fine-grained, laminated strata, characterized by few fossil remains and a darker colour related to the abundant presence of organic matter. - Facies D: Nummulites packstone. This facies crops out along the northern boundary of Facies A. Nummulites are also associated with Alveolina and abundant coral fragments. The rich Alveolina assemblages of Facies A and B contain, among others, Alveolina cremae, A. aff. croatica, A. decastroi, A. cf. dainellii, and A. distefanoi, that date the depositional system to SBZ 11 (Middle Cuisian, Lower Eocene) of Serra-Kiel et al. (1998). The preliminary interpretation of these four facies allows recognition of distinct paleoenvironments. The massive carbonates of Facies A, dominated by corals and associated with a remarkable amount of dasycladacean algae, indicate the presence of a wave-resistant structure, represented by a discontinuous alignment of small coral bioconstructions that developed in a very shallow-water environment, located within the upper part of the photic zone. This interpretation is also supported by the coalescence of these buildups with the sediments of Facies B, whose Alveolina grainston

2014 - Mediterranean corals through time: from Miocene to Present [Capitolo/Saggio]
A., Vertino; J., Stolarski; Bosellini, Francesca; M., Taviani
abstract

Stony corals, especially scleractinians, are a recurrent component of the benthic fauna of the Mediterranean basin and its Mesozoic-to-Cenozoic precursors. Both morphological and geochemical features of coral skeletons place these organisms among the most important natural paleoarchives of the Mediterranean geological history. The present day low diversity of the Mediterranean scleractinian fauna (25 genera and only 33 species) strikingly contrasts with its high diversity in the Early-Middle Miocene (over 80 genera and hundreds of species). The decline in coral richness has occurred since the late Middle Miocene onwards. This impoverishment trend was not linear, but abrupt in shallow-water environments during and immediately after the Late Miocene and more gradual since the Pliocene onwards. At the end of the Miocene, the Mediterranean coral fauna underwent a drastic modification that led to the disappearance of almost all zooxanthellate corals and the wel lestablished shallow-water coral-reef province. However, the generic diversity of azooxanthellate and deep-water corals did not undergo signifi cant modifi cations, that were instead much stronger at the end of the Pliocene and of the Pleistocene. Indeed, before the Calabrian stage, all remnant Indo-Pacifi c-like azooxanthellate genera disappeared and a clear NE Atlantic affi nity was established, whereas at the Pleistocene – Holocene boundary, there was a clear reduction in psychrospheric deep-water taxa. The causes that led to the impoverishment of the Mediterranean coral fauna diversity are complex and not all fully understood. However, there is a clear link between the coral diversity decrease, the gradual northward shift outside the tropical belt of the Mediterranean region, and the major climate modifications on a global scale during the last 20 million years.

2014 - Stratigraphy and facies analisys of the Langhian Dağpazarı reef complex (Mut Basin, Southern Turkey) [Abstract in Atti di Convegno]
Vescogni, Alessandro; Bosellini, Francesca; Cipriani, Anna; Gürler, Gonca; Ilgar, Ayhan; Paganelli, Emanuele; Chiossi, Irene .
abstract

During the Early/Middle Miocene, the eastern part of the Mediterranean region registered the narrowing, and the ultimate interruption of the connections with the Indian Ocean. This event represented one of the most important episodes in the Cenozoic evolution of the Mediterranean marine biota. For this reason, the study of Middle Miocene reefal communities from this area can offer an important contribution for the reconstruction of the palaeogeography and palaeoecological settings of the Mediterranean shallow-water, carbonate-producers. The primary aim of the present study is to provide a small-scale, detailed reconstruction of the stratigraphy and facies associations of a Langhian reef complex from the Mut Formation (Mut Basin, Southern Turkey). This study has been based on field observation and microfacies analysis, with a particular emphasis on the characterization of calcareous algae associations (both corallines and green codiacean) and coral fauna. The Dağpazarı reef represents a portion of a small, isolated carbonate platform located 12 Km north from the town of Mut. Its early Langhian age has been determined by 87Sr/86Sr isotope analyses performed on several well preserved oyster samples. Dağpazarı reef is represented by two main stratigraphic sequences separated by a major erosion surface. Only a few meters of lowermost sequences are exposed, while the upper one measures about 72 meters in thickness and is characterized by the superimposition of four different cycles. During the first cycle, the amplitude of the sea transgression allowed the growth of a massive coral framestone on the shelf-edge, associated to well developed slope deposits toward the basin. In particular, concentrations of small rhodoliths with large nuclei and laminar/columnar structure characterize the shallower part of the slope, while in the middle slope the presence of Halimeda bioherms indicates a palaeodepth of about 30/50 meters. The two subsequent cycles show the superimposition, on the shelf-edge, of two similar shallowing-upward sequences, each of them related to a small-scale, transgressive phase. In particular, each sequence exhibits at the base a coralline red algae bindstone, typical of low hydrodynamic conditions, made of thin, laminar/foliose crusts associated to discoidal/irregular rhodoliths. This facies is followed by Halimeda bioherms and biocalcarenite deposits, the latters characterized by the presence of abundant “hooked” and foliose coralline algae crusts associated to gastropods concentrations. The coexistence of the latter features within biocalcarenite deposits is considered a reliable marker of the presence of seagrass beds. Both sequences terminate with the occurrence of shallow-water, massive coral framestone on the top. The fourth Dağpazarı reef cycle developed on the shelf-edge and started with a coralline red algae bindstone, but in this case, corallines colonizations were followed by a fine-grained, mud-supported biocalcarenite whose stratification dips landward. The top of the succession is characterized by coarser biocalcarenite deposits containing small, coral patches. Due to its stratigraphic setting and composition, this last sequence has been interpreted as a back-reef facies association, related to the progradation of a reef framework (now eroded) as a consequence of a final highstand phase of the sea-level. This work provides new information on some important shallow-water carbonate producers, for example Dağpazarı Halimeda bioherms represent so far the oldest recorded examples of this kind of structures; at the same time it offers a detailed frame for further, specific studies on Middle Miocene reef-building associations.

2014 - The Dağpazarı carbonate platform (Mut Basin, Southern Turkey): facies and environmental reconstruction of a coral reef system during the Middle Miocene Climatic Optimum. [Articolo su rivista]
Vescogni, Alessandro; Bosellini, Francesca; Cipriani, Anna; G., Gurler; A., Ilgar; E., Paganelli
abstract

Plate tectonics and climate change have deeply influenced the evolution of coral reef systems of the Mediterranean during the Miocene. Most of this information is based on studies of coral reefs from the western and central sectors of th eMediterranean. This study reports facies analyses, Sr isotope stratigraphy and environmental reconstructions of the Dagpazarı coral reef system, located within the Mut Basin in Southern Turkey. Stratigraphic correlations and Sr isotope ratios on several oyster shells date the Dağpazarı reef to the early Langhian. Ten different facies have been recognized and their arrangement has led to the identification of two main depositional units. Interpretation of the biotic associations indicates that the Dağpazarı depositional system developed constantly within the euphotic zone. The reef framework was mainly built by massive faviid and poritid zooxanthellate corals, whereas loose-grain sediments were essentially produced by Halimeda, coralline red algae, or influenced by the presence of seagrass colonizations. This study highlights for the first time the great importance of Halimeda as sediment producer in the eastern Mediterranean coral reef systems. This role is related to the common occurrence of Halimeda plates within almost all the reef facies, but especially to the presence of large in situ bioherms dominated by the algal segments. Dağpazarı Langhian Halimeda bioherms also represent the oldest of these structures so far recorded in the fossil record. The development of the Dağpazarı platform was mainly controlled by eustatic fluctuations of the sea-level and by the morphology of the antecedent substrate. In particular, the occurrence of a pre-existent topographic high promoted the constant presence of shallow-water environments throughout the depositional history of the reef system, with the production of euphotic carbonates both landward and basinward and the consequent formation of a small, elliptical platform. 87Sr/86Sr ages place the Dağpazarı reef system exactly within the Middle Miocene Climatic Optimum phase, the most recent warm phase of the Earth. This suggests that zooxanthellate corals were able to exert their reef-building capacity in shallow-water settings even during periods of global warming, thus being not exclusively an adaptation to cooling climates as proposed in the recent debates.

2013 - Burdigalian coral bioconstructions of Sperone (southern Corsica) [Relazione in Atti di Convegno]
Mazzucchi, A.; Tomassetti, L. .; Bosellini, Francesca; Brandano, M.
abstract

This study reports the facies analysis of a Burdigalian mixed carbonate-siliciclastic coastal system characterized by coral bioconstructions. These deposits, assigned to the Cala di Labra Fm, represent the sedimentation occurred in the Bonifacio Basin during the Sardinia-Corsica block rotation. At Sperone, the Cala di Labra Fm is weel exposed along the sea-cliff allowing an accurate investigation and mapping of coral bioconstructions and lateral facies transition. Four principal facies have been recognized: a) siliciclastic, b) quartz-rich calcarenite, c) calcarenite and d) coral facies.

2013 - Growth and demise of a Burdigalian coral bioconstruction on a granite rocky substrate (Bonifacio Basin, South Corsica) [Articolo su rivista]
L., Tomassetti; Bosellini, Francesca; M., Brandano
abstract

During the Early Miocene, coincident with the Sardinia–Corsica block rotation, mixed carbonate–siliciclastic sediments of the Cala di Labra Formation were deposited on the southern margin of the Bonifacio Basin (southeastern Corsica, France). The Burdigalian marine transgression is spectacularly represented by a peculiar coral bioconstruction, unconformably lying on the eroded Variscan granitic basement. Superb exposures allowed detailed, three-dimensional field mapping, lithofacies analysis, and characterization of the Cala di Labra coral bioconstruction. As a result of the extremely irregular and articulated substrate, the coral buildup appears as an organized lens-shaped structure, and its core is constituted by a relatively dense coral domestone with a moderate increase of platy corals in the upper part. A coral rubble associated with granitic cobbles and pebbles is locally present at the base. The inter-coral sediment consists of poorly sorted bioclastic wackestone to packstone. Results from this study clearly show evidence for the occurrence of a former submerged granitic substrate that, as very rarely documented in the geological record, is here interpreted as the subtidal substrate for growth of a small bioconstruction under relatively high energy and clear water conditions. The Cala di Labra bioconstruction is overlain by a fining-upward quartzose conglomerate and sandstone succession interpreted as deposited in a coastal setting near fluvial point sources. The demise of coral growth was caused by a regressive event and by the consequent quite-sudden burial and related changes of trophic conditions.

2013 - The Late Miocene coldspot of z-coral diversity in the Mediterranean: patterns and causes [Articolo su rivista]
C., Perrin; Bosellini, Francesca
abstract

The Late Miocene distribution and diversity of zooxanthellate-like corals in the Mediter-ranean are analyzed in their paleobiogeographical framework, using our REEFCORALdatabase. The Late Miocene Mediterranean pool reached 20 z-coral genera. Although thisfauna could build flourishing reef ecosystems during the Early Messinian, it was a relictfauna with severely limited speciation that lived on the edge of its ecological requirementsin terms of solar energy and temperature range. Most z-coral genera, because they hadlong stratigraphic ranges and had survived previous extinctions, were able to adapt tothe Messinian environments, which were unusual for such biotas. Hence, Porites, the mostwidespread genus in the region and also the most dominant in ecological assemblages, wasthe best equipped to cope with the drastic changes related to the Messinian Salinity Crisis.

2012 - Mesophotic coral buildups in a prodelta setting (late Eocene, southern Pyrenees, Spain): a mixed carbonate-siliciclastic system. [Articolo su rivista]
M., Morsilli; Bosellini, Francesca; L., Pomar; P., Hallock; M., Aurell; Papazzoni, Cesare Andrea
abstract

Lower Priabonian coral bioherms and biostromes, encased in prodelta marls/clays, occur in the Aınsa-Jaca piggyback basin, in the South Central Pyrenean zone. Detailed mapping of lithofacies and bounding surfaces onto photomosaics reveals the architecture of coral buildups. Coral lithosomes occur either isolated or amalgamated in larger buildups. Isolated lithosomesare 1 to 8 m thick and a few hundred metres wide; clay content within coral colonies is significant. Stacked bioherms form low-relief buildups, commonly 20 to 30 m thick, locally up to 50 m. These bioherms are progressively younger to the west, following progradation of the deltaic complex. The lowermostskeletal-rich beds consist of bryozoan floatstone with wackestone to packstone matrix, in which planktonic foraminifera are abundant and light-related organisms absent. Basal coral biostromes, and the base of many bioherms, consist of platy-coral colonies ‘floating’ in a fine-grained matrix rich inbranches of red algae. Corals with domal or massive shape, locally mixed with branching corals and phaceloid coral colonies, dominate buildup cores. These corals are surrounded by matrix and lack organic framework. The matrix consists of wackestone to packstone, locally floatstone, with conspicuous red algal and coral fragments, along with bryozoans, planktonic and benthonicforaminifera and locally sponges. Coral rudstone and skeletal packstone, with wackestone to packstone matrix, also occur as wedges abutting the buildup margins. Integrative analysis of rock textures, skeletal components, buildup anatomy and facies architecture clearly reveal that these coral buildups developed in a prodelta setting where shifting of delta lobes or rainfall cyclesepisodically resulted in water transparency that allowed zooxanthellate coral growth. The bathymetric position of the buildups has been constrained from the light-dependent communities and lithofacies distribution within thebuildups. The process-product analysis used here reinforces the hypothesis that zooxanthellate corals thrived in mesophotic conditions at least during the Late Eocene and until the Late Miocene. Comparative analysis with some selected Upper Eocene coral buildups of the north Mediterranean area show similarities in facies, components and textures, and suggest that they also grewin relatively low light (mesophotic) and low hydrodynamic conditions.

2012 - Paleobiogeography of scleractinian reef corals: Changing patterns during the Oligocene–Miocene climatic transition in the Mediterranean [Articolo su rivista]
C., Perrin; Bosellini, Francesca
abstract

During the Oligocene–Miocene Greenhouse-to-Icehouse climatic transition, the biogeography of reef corals or zooxanthellate-like scleractinian corals was gradually changing from a pan-tropical Tethyan Province in the Eocene to three reef-coral Provinces of the Western Atlantic–Caribbean, Indo-Pacific and Mediterranean.Our REEFCORAL database encompasses updated and homogenized data on paleoenvironmental and systematicsof scleractinian corals occurring in the Oligocene and Miocene outcrops from circum-Mediterranean regions, provided by most of relatively recently published data in the literature and by the study of published and unpublished collections of coral specimens from the same area, including the important collections housed at the MNHN (Paris) and our own collections. As there is no validated direct criterion for the identification of the coral-zooxanthellate symbiosis in the fossil record, and considering the difficulty to use the biogeochemical approaches in the context of this study, the subjectivity of the morphological criteria and the relative recent age of the fossil corals we are dealing with, a uniformitarian approach has been used for inferring the symbiotic status of scleractinian genera in REEFCORAL. Among the 158 genera included in our database, 93 can be considered as zooxanthellate and 10 have a doubtful zooxanthellate status. This relativelyexhaustive database was used to reconstruct the temporal and spatial distribution of scleractinian corals in the Mediterranean during the Oligocene–Miocene time in order to discuss the interplaying effects of the global cooling at that time, the re-organization of the Tethyan realm resulting from the African, Arabian and Eurasian plate collision and the emergence of the Alpine chains, driving the gradual northward movement of the whole region outside the tropical/subtropical belt. It is shown that the structure of the Mediterranean z-coral Oligocene–Miocene paleobiodiversity was characterized by many geographically-restricted genera with a moderate to short stratigraphical range and a few long-ranging widespread genera. A major consequence of this structure is that the extinction pattern has proceeded through the preferential extinction of rare-occurrence genera through time. The potential rapid long-distance dispersal of most coral larvae compared to the size of the Oligocene–Miocene Mediterranean, explains why no biogeographical subprovinces can be distinguished for the z-coral fauna. On a local scale,ecological processes tend to sort coral taxa by limiting z-coral development to geographically restricted and discontinuous areas. This accounts for the large amount of geographically-restricted taxa forming the Mediterranean coral fauna.The interaction of plate-tectonics, Alpine orogenesis and climate at local to subregional scales exerts strong controls over the spatio-temporal distribution of z-coral assemblages within the circum-Mediterranean realm. In particular, we suggest that the richness and composition of the Eastern Atlantic coral fauna are indirectly related to the opening and closure of the eastern seaway connection with the Indian Ocean, which controlled the E–W circulation of surface waters and hence the westwards dispersal of pelagic larvae. At the scale of the whole region, the gradual regional climatic change produced by the northwards migration of the entire area, superimposed on the global cooling, appears in large part responsible for the extinction pattern of z-corals through time in the Mediterranean biogeographical Province.

2011 - Microtaphofacies analysis of lower Oligocene turbid-water coral assemblages [Articolo su rivista]
Silvestri, Giulia; Bosellini, Francesca; J. H., Nebelsick
abstract

The presence, distribution, and preservation of coral-rich facies in the lower Oligocene Gornji Grad Beds of Slovenia are analyzed using a microtaphofacies approach. This method allows taphonomic signatures to be recognized in thin section along with the presence of coral specimens and growth forms within and between stratigraphic logs. Coral-dominated limestones within the Gornji Grad Beds are represented by rudstones in a packstone-wackestone matrix. The conditions are generally reconstructedas turbid water due to the prevalence of muddy carbonate matrix, which also leads to excellently preserved morphological features in thin section. These beds represent a reference area for the study of Paleogene corals, especially during the Oligocene, a key phase of reef development during the Cenozoic. This study also contributes to the characterization of fossil reefs in turbid-water environments. The evaluated coral fauna is dominated by delicate-branching Stylophora and Acropora, although thickly branching (Actinacis, Goniopora), phaceloid (Caulastrea), and massive forms (Alveopora, Astreopora, Antiguastrea) also occur. Assessed taphonomic signatures include fragmentation, abrasion, bioerosion, and encrustation. Three types of bioerosion traces are distinguished (Entobia, Gastrochoenolites, Trypanites). Encrustation includes both thincrusts and complex multi-taxon sequences dominated by coralline algae. Five microtaphofacies are distinguished based on variation of taphonomic signatures, taxonomic composition, and growth forms. Differences in microtaphofacies are interpreted with respect to turbidity, sediment accumulation, and water turbulence; both parautochthonous and allochthonous deposits are reconstructed. A depositional model based on the distribution of microtaphofacies in the studied sections shows a succession of coral communities with different colonization strategies reflecting generally high stress levels.

2010 - Coral Buildups in Mesophotic, Siliciclastic Prodelta Settings (Late Eocene, Southern Pyrenees, Spain): An As Yet Unexplored Play? [Articolo su rivista]
M., Morsilli; Bosellini, Francesca; L., Pomar; P., Hallock; M., Aurell; Papazzoni, Cesare Andrea
abstract

Cenozoic zooxanthellate corals are commonly considered to form framework-dominated buildups in shallow, well illuminated (euphotic) and oligotrophic conditions. In contrast, detailed outcrop study and facies-component analysis show that Eocene non- framework coral buildups also developed in turbid, poorly illuminated (mesophotic) and relatively nutrient-rich conditions. The study area is located in the South-Central Pyrenean Zone (Jaca Basin). Here, middle to upper Eocene prodelta clay/marl succession passes up-section into prograding delta-front sandstones and, subsequently, into continental sandstones and conglomerates. Coral-rich lithosomes occur in the upper part of the clay/marls succession and are completely encased in clay.Within coral buildups, facies consist of: 1) coral boundstone with different coral growth fabrics (platestone and domestone, and subordinate pillarstone and mixstone) and abundant red algae, in a mud-dominated matrix; 2) well sorted fine-grained or poorly sorted coarse-grained skeletal packstones with abundant coral fragments, red algae, bryozoans, benthonic foraminifers and rare planktonic foraminifers, locally rich in larger benthic foraminifers and siliciclastic sand; 3) red-algae-rich coral rudstone with pack-wackestone matrix; 4) bryozoan floatstone in a mud-dominated matrix. These carbonate lithofacies pass laterally and vertically into 4) thinly laminated clay to marls with interbedded sandstone beds.Coral boundstone and associated packstone and rudstone wedges form single bioherms and discrete biostromes (1-8 m thick) that stack into larger carbonate buildups, commonly 20-30-m thick, with some up to 50-m thick. Facies associations, textures, and photo-dependent components indicate these buildups to have grown in the mesophotic (lithofacies 1, 2 and 3) and aphotic (lithofacies 4) zones and in low energy conditions below fair-weather wave base, where they were only occasionally hit by exceptional storms. Dominance of corals and bryozoans (plankton catchers) over sponges and molluscs (plankton pumpers) indicates predominance of phyto- and zooplankton over picoplankton, which suggest mesotrophic conditions.Our results highlight the contrast with present-day “classic” reef models and suggest that by the late Eocene reef coral assemblages where able to thrive in low-light, low-energy, turbid and nutrient-rich conditions. The location of these coral buildups, encased in prodelta clays, can be regarded as a new, unexplored, potential play.ReferencesBerner, R.A., and Z. Kothavala, 2001, GEOCARB III: A revised model of atmospheric CO2 over Phanerozoic time: American Journal of Science, v. 301, p. 182-204.Demicco, R.V., T.K. Lowenstein, and L.A. Hardie, 2003, Atmospheric pCO2 since 60 Ma from records of seawater pH, calcium, and primary carbonate mineralogy: Geology, 31, p. 793-796.Dreyer, T., J. Corregidor, P. Arbues, and C. Puigdefabregas, 1999, Architecture of the tectonically influenced Sobrarbe deltaic complex in the Ainsa Basin, northern Spain: Sedimentary Geology, v. 127-3-4, p. 127-169.Hallock, P., and L. Pomar, 2009, Cenozoic evolution of larger benthic foraminifers: Paleoceanographic evidence for changing habitats: Proc. 11th International Coral Reef Symposium, Ft. Lauderdale, Florida, 7-11 July 2008, v. 1, p. 16-20.Lear, C.H., H. Elderfield, and P.A. Wilson, 2000, Cenozoic deep-sea temperatures and global ice volumes from Mg/Ca in benthic foraminiferal calcite: Science, v. 287/5451, p. 269-272.Liebau, A., 1984, Grundlagen der Ökobathymetrie, Paläontologische Kürsbucher, v. 2, p. 149-184.Millán, H., M. Aurell, and A. Meléndez, 1994, Synchronous detachment folds and coeval sedimentation in the Prepyrenean External Sierras (Spain): a case study for a tectonic origin of sequences and systems tracts: Sedimentology, v. 41, p. 1001-1024.Pagani, M., J.C. Zachos, K.H. Freeman, B. Tipple, and S. Bohaty, 2005, Marked decline in atmospheric carbon dioxide

2010 - Coral Buildups in Oligophotic, Nutrient‐Rich, Siliciclastic Prodelta Settings (Late Eocene, Southern Pyrenees, Spain): An As Yet Unexplored Play? [Abstract in Atti di Convegno]
M., Morsilli; Bosellini, Francesca; L., Pomar; M., Aurell; Papazzoni, Cesare Andrea
abstract

Cenozoic zooxanthellate corals are commonly considered to form framework‐dominated buildups in shallow‐, well‐illuminated (euphotic) and oligotrophic conditions. In contrast, detailed outcrop study and facies‐component analysis show that Eocene non‐framework coral buildups also developed in turbid, oligophotic (poorly illuminated) and nutrient‐rich conditions. The study area is located in the South‐Central Pyrenean Zone (Jaca Basin). Here, middle to upper Eocene prodelta clay/marl succession passes, up‐section, into prograding delta‐front sandstones and, subsequently, into continental sandstones and conglomerates. Coral‐rich lithosomes occur in the upper part of the clay/marls succession and are completely encased in clay.Within coral buildups, facies consist of: 1) coral boundstone with different coral growth fabrics (platestone and domestone, and subordinate pillarstone and mixstone) and abundant red algae, in a mud‐dominated matrix; 2) well‐sorted fine‐grained or poorly‐sorted coarse‐grained skeletal packstones with abundant coral fragments, red algae, bryozoans, benthonic foraminifers and rare planktonic foraminifers, locally rich in larger benthic foraminifers and siliciclastic sand; 3) red‐algae‐rich coral rudstone with pack‐wackestone matrix; 4) bryozoan floatstone in a mud‐ dominated matrix. These carbonate lithofacies pass, laterally and vertically into 4) thinly laminated clay to marls with interbedded sandstone beds. Coral boundstone, and associated packstone and rudstone wedges, form single bioherms and discrete biostromes (1‐8 m thick) that stack into larger carbonate buildups, commonly 20‐30‐m thick, with some up to 50‐m thick. Facies associations, textures and photo‐dependent components indicate these buildups to have grown in the oligophotic‐ (lithofacies 1, 2 and 3) and aphotic (lithofacies 4) zones, and in low energy conditions below fair‐weather wave base, where they were only occasionally hit by storms. Dominance of corals and bryozoans (plankton catchers) over sponges and mollusks (plankton pumpers) indicates predominance of phyto‐ and zooplankton over picoplankton, which suggest mesotrophic conditions.Our results highlight the contrast with present‐day “classic” reef models, and suggests that by the late Eocene reef coral assemblages where able to thrive in low‐light, low‐energy, turbid and nutrient‐rich conditions. The location of these coral buildups, encased in prodelta clays, can be regarded as a new, unexplored, potential play.

2010 - Coral diversity and temperature: a palaeoclimatic perspective for the Oligo-Miocene of the Mediterranean region. [Capitolo/Saggio]
Bosellini, Francesca; C., Perrin
abstract

Zooxanthellate-coral (z-coral) generic richness values from 102 Oligocene-Miocene localities from the Mediterranean and adjacent areas are tested in this paper as a proxy for relativepalaeotemperatures, essentially using the quantitative relationship between taxonomic richness and prevailing seawater temperature underlined by the so-called ‘energy hypothesis’. Patterns of generic richness and inferred palaeotemperatures areexamined for each stage of the Oligocene-Miocene time interval and compared with some global palaeoclimatic curves based on oxygen stable-isotopes. Except for the Mid-Miocene Climatic Optimum, which is not recorded in the generic richness of theMediterranean z-coral communities, the coral-richness-derived palaeotemperatures correlate well with the general palaeoclimatic trends shown by the isotope curves.Results also show: (1) a gradual increase of temperature from the early to the late Rupelian; and (2) a gradual widening of the temperature range after the Burdigalian. The latter indicates that z-coral communities were able to maintain themselves in the region by progressively adapting to a wider temperaturerange from the mid-Miocene onwards to the Messinian, as the Mediterranean was migrating northward. Although limitations and biases are underlined and discussed in the paper, the ‘energy hypothesis’ applied to fossil z-coral faunas appears to offer a powerful method when used at global or regional scales toestimate changes in palaeotemperatures. It holds particular promise for time intervals and regions where conventional isotopic data are lacking, such as the Oligocene and Miocene of the Mediterranean.

2010 - Coral diversity and temperatures: a paleoclimatic perspective for the Oligo-Miocene of the Mediterranean region [Capitolo/Saggio]
Bosellini, Francesca; C., Perrin
abstract

Zooxanthellate-coral (z-coral) generic richness values from 102 Oligocene-Miocene localities from the Mediterranean and adjacent areas are tested in this paper as a proxy for relative palaeotemperatures, essentially using the quantitative relationship between taxonomic richness and prevailing seawater temperature underlined by the so-called‘energy hypothesis’. Patterns of generic richness and inferred palaeotemperatures areexamined for each stage of the Oligocene-Miocene time interval and compared with some global palaeoclimatic curves based on oxygen stable-isotopes. Except for the Mid-Miocene Climatic Optimum, which is not recorded in the generic richness of theMediterranean z-coral communities, the coral-richness-derived palaeotemperatures correlate well with the general palaeoclimatic trends shown by the isotope curves.Results also show: (1) a gradual increase of temperature from the early to the late Rupelian; and (2) a gradual widening of the temperature range after the Burdigalian. The latter indicates that z-coral communities were able to maintain themselves in the region by progressively adapting to a wider temperaturerange from the mid-Miocene onwards to the Messinian, as the Mediterranean was migrating northward. Although limitations and biases are underlined and discussed in the paper, the ‘energy hypothesis’ applied to fossil z-coral faunas appears to offer a powerful method when used at global or regional scales toestimate changes in palaeotemperatures. It holds particular promise for time intervals and regions where conventional isotopic data are lacking, such as the Oligocene and Miocene of the Mediterranean.

2010 - Depositional model and paleodepth reconstruction of a coral-rich, mixed siliciclastic-carbonate system: the Burdigalian of Capo Testa (northern Sardinia, Italy) [Articolo su rivista]
M., Brandano; L., Tomassetti; Bosellini, Francesca; A., Mazzucchi
abstract

This study presents a detailed facies analysis and paleodepth reconstruction of a coral-rich mixed siliciclastic-carbonate system Burdigalian in age, outcropping in the northern sector of Sardinia(Capo Testa). Excellent exposures of continuous sea-cliff outcrops around the south-western and north-eastern of Capo Testa promontory allowed us to: 1) trace stratigraphic surfaces; 2) document stratal geometries; 3) discern details of the lithofacies and, 4) reconstruct the paleodepths of the different depositional environments. A total of seven sedimentary facies has been recognized and interpreted: siliciclastic conglomerate and coarse bioclastic sandstone (F1), fine- to the medium-grained hybrid sandstone (F2, scleractinian coral domestone (F3), bioclastic packstone to floatstone with platy Porites (F4), red algae floatstone to rudstone (F5), larger benthic foraminifers (LBF) bioclastic rudstone floatstone in a packstone matrix(F6), molluscan floatstone in a bioclastic packstone matrix (F7). The investigated system is characterized by nearshore to shoreface deposits with a conspicuous terrigenous content that grades seaward into deeper zones where coral patch-reefs developed in association with adjacent areas colonized by seagrass meadows. The more distal facies are constituted by scattered encrusting tabular colonies of Porites in growth position occurring in a deeper and lower energy environment.The paleodepth interval that is observed in the Capo Testa outcrop ranges from 0 to 50 m.

2010 - Rhodolith-rich lithofacies of the Porto Badisco Calcarenites (upper Chattian, Salento, southern Italy) [Articolo su rivista]
M., Brandano; M., Morsilli; G., Vannucci; M., Parente; Bosellini, Francesca; G., Mateu Vicens
abstract

This study describes the rhodolith-rich lithofacies of the PortoBadisco Calcarenites, an upper Chattian rhodalgal/larger foraminiferaldominated unit exposed in the southern part of the Apulia Carbonate Platform (Salento Peninsula, Italy). The lensoid rhodolith-rich lithosome at the base of the studied section is made of rhodolith rudstone and floatstone which infill a channel-like depression inherited from the substrate.Changes in the texture of the rhodolith facies and in the innerstructure of the rhodoliths reflect variations in submarine currentvelocity across the section of the channel. Inherited topography controlled both the locus and the mode of rhodolith accumulation.The rhodolith lithosome is bounded by a flat surface abovewhich rhodoliths are notably absent and beds are tabular. Thisimplies that rhodolith accumulation ended as soon as substratetopography was completely levelled off. The taxonomic composition of the red algal and larger foraminiferal assemblages suggests that the rhodolith-rich unit deposited in the oligophotic zone. The abundance of tropical genera among the coralline algae (Lithoporella and Sporolithon) and the high diversity of larger foraminiferal assemblages indicate that the deposition of the Porto Badisco Calcarenites took place in the warm waters of the tropical to subtropical zone.

2009 - A taphonomic approach to coral reef study: examples from the Oligocene of the Piedmont Basin (NW Italy) and Gornji Grad Beds (Slovenia). [Abstract in Rivista]
Silvestri, Giulia; Bosellini, Francesca; Morsilli, M.; Nebelsick, J.
abstract

Taphonomy is the study of those post-mortem processes which affect organisms and their skeletons through biological, physical and chemical alterations. The taphonomic history of a fossil assemblage can provide a wide range of information concerning environmental conditions and ecological relationships of the living community including causes of death, biological and physical processes on the sediment surface, rates of transport, surface residence times before burial and diagenesis. Taphonomic analysis can ultimately reveal processes and patterns not readily recognizable by other palaeoecological or sedimentological approaches. A far as coral reefs are concerned, there has been the tendency to consider them as examples of preserved life assemblages. As a consequence, taphonomic approaches to the study of corals and coral reefs are relatively rare. Nevertheless, the development and demise of coral reef frameworks and the preservation potential of both in situ and rubble coral assemblages are strictly related to taphonomic processes such as, for example, physical disturbance (storm events and terrestrial run-off) and bioinfestation on both living and dead corals. Taphonomic signatures are especially significant in reconstructing environmental conditions associated to scleractinian-dominated turbid-water bioconstructions (TWBs) thriving in episodically or permanently turbid waters where marine environmental parameters often approach the threshold levels for tropical carbonate production.Coral assemblages from the Oligocene of the Piedmont Basin (NW Italy) and the Gornji Grad Beds (Slovenia) represent an example of “reefs” developed in nearshore deltaic turbid-water settings. Within these two case studies we present here preliminary results of a taphonomic approach using microfacies analysis as a tool to infer the incidence of controlling factors as terrigenous input, reduced light penetration and turbidity. Our analysis is particularly focused on primary processes occurring on coral remains before or during sedimentation, especially fragmentation and bioinfestation. Microfacies analysis shows: 1) generally low incidences of fragmentation; 2) low rates of abrasion of coral clast boundaries; 3) an inverse relationship between fragmentation and bioinfestation. Bioinfestation is a process involving both bioerosion and encrustation. In contrast to bioerosion, which represents a destructive process due to grazers and boring organisms (such as clionid sponges and boring bivalves), encrustation is a constructive and stabilizing process mainly represented in the studied material by coralline algae and encrusting foraminifera. This process can affect both living and dead substrates. With respect to bioinfestation: 1) Encrustation and bioerosion are typically sparsely distributed among coral clasts and also within the same coral fragment; 2) Bioerosion is inversely correlated with terrigenous input; 3) The degree of infestation by boring organisms is also dependent on coral morphology and skeletal architecture: in fact branching corals are more susceptible to bioerosion and among these, Stylophora is more susceptible than Acropora; 4) The dependence of encrustation on a specific controlling ecological factor is still unclear. Through this taphonomic approach it was possible to infer for both study areas a muddy environment with a generally low hydrodynamic regime, dominated at least occasionally by high turbidity and/or sedimentation. Sediment-resistants and fast-growing coral morphologies were promoted and the production of dead coral rubble was frequent, especially during phases of abundant terrigenous run-off from rivers. Nevertheless, the rate of transport for coral clasts was low, such that these assemblages were deposited almost in situ. Surface residence times of coral rubble before burial was very variable and was probably the main factor controlling incidences of bioinfestation, which is typically not homogenous.

2009 - Coralline algae (Corallinales, Rhodophyta) in western and central Mediterranean Messinian reefs [Articolo su rivista]
J. C., Braga; Vescogni, Alessandro; Bosellini, Francesca; J., Aguirre
abstract

Coralline algae are common components in Messinian reefs in the Sorbas Basin in SE Spain and in the Salento Peninsula (southern Italy). They occur encrusting coral skeletons and other bioclasts, forming rhodoliths, and as fragments in back-reef, reef-framework, and proximal-to middle slope facies. Corallines also occur in Halimeda boundstones associated to coral reefs. Incontrast, no coralline algae have been recorded in the fine-grained distal slope deposits in both areas and lagoonal marly limestones in Salento. The relative abundance of corallines in reefs and their species richness is significantly higher in the Salento platform than in the intermontane Sorbas Basin, which was affected by terrigenous influx. Neogoniolithon brassica-florida and Spongites fruticulosus dominate the shallow-water assemblages; Lithophyllum records peak at the base ofreef-core and upper slope deposits (around 20 m palaeodepth) and Phymatolithon calcareum and species of Lithothamnion are most abundant in deeper slope facies. The main components of the Messinian Mediterranean reef coralline assemblages are extant species, common in the Mediterranean and along the north Atlantic coast from Morocco (and the Canary Islands) to theBritish Islands. A few, such as Spongites fruticulosus and Phymatolithon calcareum, have been living in the Mediterranean region for more than 25 Ma. Four species still live in the Indo-Pacific but disappeared from the Mediterranean during the Messinian Salinity Crisis. The typical componentsof present-day Indo-Pacific coral reefs do not occur in the Mediterranean Messinian reefs. The 'Mediterranean-Atlantic' character of the Messinian reef corallines reflects the decrease in tropical biotas in the Mediterranean throughout the Miocene, probably related to global cooling and isolation of the Mediterranean from the Indian Ocean since the Middle Miocene.

2009 - Evolutionary patterns of Mediterranean Oligocene-Miocene reef corals [Abstract in Rivista]
Bosellini, Francesca; C., Perrin
abstract

Tracing evolution of reef-coral genera (zooxanthellate-like scleractinian corals) during the Oligocene and Miocene in the Mediterranean region is certainly a main goal to achieve in order to understand a complex palaeogeographic and climatic history, with stepwise transition towards cooler climates, biotic turnovers and the almost complete disappearance of zooxanthellate corals near the end of the Miocene.The dataset used for this work is based on our REEFCORAL database, that currently hosts data on more than 3000 occurrences of coral genera from 285 Oligocene and Miocene localities in the circum-Mediterranean regions, including the Mediterranean, the Paratethys, and some Middle-East and Eastern Atlantic areas. Up-dating and homogeneization of stratigraphical data associated to each coral occurrence, together with some needed systematic revision for some scleractinian genera, were made before entering the related information in the database. Although some stages or areas appear less represented than others, because of poor investigation, or limited stratigraphic resolution, or even non availability of outcrops, the broad geographic and temporal distribution of the different coral localities is considered to be satisfactorily representative of the whole “Mediterranean”region both in time and space.Evolution of reef coral generic diversity during the Oligocene and Miocene is traced by analyzing richness, extinction and origination curves for genera over this period.The Mediterranean generic pool of zooxanthellate-like corals during Oligocene-Miocene time includes 102 genera. Temporal changes of generic richness show an increase from Rupelian to Chattian followed by a marked decrease in the Aquitanian. The number of genera is increasing again in the Burdigalian and is then characterized by a continuous decline towards the end of the Miocene.By the production of a stratigraphic range chart, number of originations and extinctions per stage have been also calculated. Different curves have been produced in order to minimize potential biases, considering in particular the genera which are known from a unique locality in the Mediterranean Province and hence which can be related either to a true very rare occurrence in space and time or in some case to taxonomical-identification bias. Variation in the duration of stage also can introduce a biased pattern in coral evolution. Therefore, origination and extinction curves have been weighted by stage duration.The main characteristic of the evolutionary curves is that while originations are more important than extinctions during the Oligocene, this is clearly reversed from the Aquitanian onwards. During the Miocene, the number of originations is decreasing from the Burdigalian to the Serravallian while the extinctions remain broadly stabilized during the same time interval. This is followed by a drastic decrease of both originations and extinctions during the Upper Miocene. The marked increase of the extinction curve in the Messinian is due to the disappearance of the Mediterranean reef-coral fauna at the end of this stage. The Oligocene can be seen as period with important evolutionary turnovers as, both for Rupelian and Chattian, extinctions are in some way associated to originations, suggesting this period as characterized by good recovery conditions. This is in contrast with Miocene evolutionary patterns, also underlined by the comparison of the generic richness curve with the extinction and origination curves. In particular, the proportion of genera extinct compared to the Mediterranean generic pool at the same time is clearly increasing during the whole Miocene excepted during the Tortonian time.Moreover, while the evolutionary pattern during the Oligocene is in good accordance with that known in other reef-coral provinces, and at the global scale; the Miocene evolution of Mediterranean reef-corals appears mainly driven by regional en

2009 - Geochemical proxy data from reef systems suggests high salinity variability and stable sea level within the Mediterranean region during the Messinian prior to the MSC. [Abstract in Atti di Convegno]
Brachert, T. C.; Vescogni, Alessandro; Mertz Kraus, R.; Bosellini, Francesca; Reuter, M.
abstract

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2009 - Macrofauna associated with the Pleistocene limestones of Zabargad Island (Red Sea): paleoenvironmental and stratigraphic significance. [Abstract in Rivista]
Taviani, M.; Ceregato, A.; Bosellini, Francesca; Veronesi, F.
abstract

In 1979 an Italian geological mission visited Zabargad island (St. John’s: 23°37’ N, 36°12’ E). The island, located about 50 Km W of its axis, is considered key area to understanding the kinematics of the Red Sea rift. Giorgio Marinelli, who was in the party carrying out the first field reconnaissance, inspired this trip, followed by two other expedition sin 1980 and 1983. Thought to be an uplifted block of upper mantle and crustal rocks, Zabargad exposes a unique suite of rocks that are: (1) Fresh peridotites; (2) Metamorphic rocks (gneiss and amphibolites); (3) Doleritic-basaltic dikes; (4) Sandstone, limestone, and black shale of the Zabargad Formation (Early Cretaceous); (5) Evaporites (Miocene); (6) Old Reef Limestones; (7) Old conglomerates and breccias; (8) Young Reef Limestones (MIS5e and Holocene). The Old Reef Limestones (ORL) is an informal stratigraphic unit represented by diachronous fossiliferous biocalcarenites and reefal limestones. Although very fossiliferous, this unit has been affected by considerable diagenetic processes and most of its fossil content is now represented by moulds of corals, molluscs, echinoids, barnacles and coralline algae. ORL is tentatively assigned to the Pleistocene, although the concomitant absence of planktonic microfossils and the lack of radiometrically-datable macrofossils hamper at present a more precise age assessment. Preserved shells or latex and gypsum casts at times permit a more refined taxonomic identification and with no exception the fossils are consistently approachable to taxa inhabiting the present Red Sea-Indian Ocean region and at times known from Pleistocene outcrops in the Red Sea region. This similarity permits to drive some regarding the marine setting of Zabargad during the pre-MIS5 Pleistocene suggesting that ORL represents coral reefal and shallow lagoonal environments. The presence around Zabargad of shallow coral reef environments is unquestionably documented by various massive, branching and encrusting zooxanthellate scleractinian corals such as: Porites (massive and columnar growth forms), Stylophora, Acropora, Cyphastrea, Favites, Favia, Pavona, Goniopora, Caulastrea (phaceloid colony) and the solitary coral Fungia. The occurrence of the infaunal bivalve Periglypta and epifaunal pectinids is consistent with reefal habitats. The presence of shallow marine lagoons (backreef?) entering depressed areas pf the island’s interior is documented by infaunal bivalves (e.g. Diplodonta) and gastropods (e.g. Strombus). ORL represents the first unequivocal proof that the Zabargad peridotitic block was already an island at the time of its deposition in the pre-MIS5 Pleistocene (> 125ky BP), thus setting a minimum age for its alleged tectonic uplift.

2009 - Oligophotic coral bioherms in a terrigenous prodelta setting (Late Eocene, Southern Pyrenees, Spain) [Abstract in Atti di Convegno]
Morsilli, M.; Bosellini, Francesca; Pomar, L.; Aurell, M.; Papazzoni, Cesare Andrea
abstract

Recent studies in the present oceans have shown that corals and coral reefs can thrive in episodically or permanently turbid waters with moderate to high terrigenous sediment supply. Many coral bioconstructions in the past are associated with marly and mixed carbonate-siliciclastic sediments suggesting that an actualistic approach (shallow, clear and oligotrophic waters associated with high energy settings), where zooxanthellate corals are able to build up to sea level, cannot be truly applied.The study area is located in the southern part of the Jaca Basin, a piggyback basin of the South Pyrenean foreland. Here, a late Eocene thick pile (1 km) of marls and some interbedded limestone (Arguis Fm.) passes up section to westward prograding shallow marine and deltaic deposits (Belsue-Atarés Fm to Yeste-Arrés Fm) and to continental clays, sandstones and conglomerates (Campodarbe Fm). Within the Arguis Fm, coral-rich bodies deposited during the early Priabonian, interfingered and covered by clays and sandstone. Individual coral lithosomes are mostly nodular to wavy, 1 to 8 m thick, boundaries are irregular to sharp, and clay content is significant. They stack vertically, forming low relief lens-shaped bioherms, commonly 20-30 m thick, up to 50 m. These bioherms grew within prodelta marls, being progressively younger basinward. Main bio-lithofacies are: 1) floatstone to rudstone with large fragments of corals (Cyathoseris, Actinacis, Colpophyllia, Stylophora, Caulastrea, Astrocoenia, Goniopora, Astreopora, Siderastrea, Alveopora, Agathiphyllia), branching and encrusting red algae, bryozoans and scattered bivalves, encrusting foraminifera (eg. Miniacina sp.), with wackestone to packstone matrix; 2) coral framestone with branching to meandroid corals in growth position (Caulastrea, Actinacis, Cereiphyllia, Leptoria); 3) wackestone to mudstone with platy corals encrusted by bryozoans and laminar coralline red algae, rare planktonic foraminifera; 4) grainstone to rudstone with branching coralline red algae, bryozoans and abundant miliolids, small rotalids, ostreids fragments; 5) sandstone with abundant nummulitids and coral fragments, gastropods, bryozoans, bivalves and coralline red algae fragments. Bio-lithofacies 4 and 5 are mainly developed on the flanks of the bioherms. In some outcrops, Acanthochaetetes, a demosponge that seems to be characteristic of reduced light conditions in cryptic or fore reef settings, is also present. Among larger foraminifera, the presence of Asterocyclina, Heterostegina, Operculina and the abundance of the encrusting genus Miniacina could also suggest an oligophotic paleoenvironment.These bioherms, located inside prodelta marls, grew in a relatively low to moderate energy setting, below the fair-weather wave base. Our results highlights the contrast with present-day “classic” reef models, and suggests that by the late Eocene reef coral assemblages where able to thrive in relatively deep (oligophotic), low-energy and turbid conditions.

2009 - Proposal to establishing paleontological sites in the Emilia-Romagna region (N.Italy) [Abstract in Rivista]
Ceregato, A.; Bosellini, Francesca; Conti, Stefano; Iaccarino, S.; Landini, W.; Monegatti, P.; Papazzoni, Cesare Andrea; Taviani, M.
abstract

Region Emilia-Romagna in Northern Italy hosts a variety of valuable paleontological sites of late Tertiary age that merit protection and management for public interest. Such an impressive marine invertebrate legacy is known since over three centuries and has been functional to a number of taxonomic, stratigraphic and paleoenvironmental studies. In addition, there are also many remarkable plant and vertebrate sites in need of protection and visibility. As a first step in this direction, we have selected four sites of relevant paleontological significance. They are from NW to SE: (1) Stirone River, (2) Monticino, (3) Montepetra, and (4) Mondaino, all easily accessible from local roads.(1) The Stirone River (Parma Province) cuts through a Miocene-Pleistocene sedimentary succession useful to correlate major geological and paleoclimatic events at regional and global scales. Its outstanding paleontological content has been already recognized long ago leading to the establishment of the Regional Fluvial Park in 1988. Highlights of this paleontological site exceedingly rich in marine molluscs, brachiopods, corals, calcareous algae, echinoids, bryozoans, foraminifera, etc., are a Pliocene-age chemoherm containing various lucinid clams and the Early Pleistocene “Cascatelle” Calcarenite. This paleo-site also provided important vertebrates, namely two Pliocene whales and a Pleistocene rhinoceros.(2) The Monticino Geopark, established near Brisighella (Ravenna Province), comprehends a large area along the left side of the Lamone River characterized by a spectacular Neogene succession. The dismissed Li Monti quarry that exposes upper Tortonian-lower Pliocene deposits, including a complete Messinian succession, represents the core of this Geopark. The highly remarkable paleontological content of this site refers to Tortonian-lower Messinian marine deep-water faunas, well-preserved fossil fishes within intra-evaporitic anoxic layers, late Turolian-age vertebrate remains encased in karst-infilling continental sediment dikes, brackish Lago-mare molluscs of the Colombacci Formation and early Pliocene deep-sea invertebrates of the Argille Azzurre Formation.(3) The village of Montepetra (Forlì-Cesena Province) is partially built over an impressive methanogenetic chemoherm with associated chaotic levels belonging to the Miocene-age “Lucina Limestone” informal stratigraphic unit. The main limestone body is enclosed in slope hemipelagites of the Miocene Marnoso-Arenacea foredeep succession and considered Tortonian in age. The “Lucina Limestone” of Montepetra gained international reputation as a remarkable example of deep-sea hydrocarbon seepage. Its paleontological content includes a diverse chemosynthetic macrofauna (solemyid, bathymodiolinid and lucinid bivalves; tubeworms) as well as gastropods, corals and other marine invertebrates.(4) The Miocene fossil fish fauna of Mondaino (Rimini province) was cited already in 1832 (“mummified bodies”) and later described by Luis Agassiz. This rich pre-evaporitic ichtyofauna is sourced from diatomaceous sediments (tripoli), at present clearly visible on the northern side of the Il Monte hill, near La Celletta as a consequence of the 1983 landslide. The fossil legacy contains a diverse benthic and epipelagic fauna with fish assemblages dominated by Myctophidae. Terrestrial fossils include rare insects and birds and abundant flora. This potential paleontological site is already served by a dedicated museum that preserves an important collection from the local tripoli.

2009 - The paleontological apulian heritage: a preliminary list [Abstract in Rivista]
Landini, W.; Bianucci, G.; Bosellini, Francesca; Carnevale, G.; D'Alessandro, A.; Vescogni, Alessandro
abstract

Five paleontological sites have been selected, on the bases of their scientific importance, their main paleontological features and their potential enhancement.Nardò: an important cretaceous fish assemblage of the Tethyan realmUpper Cretaceous (Coniacian-early Campanian) fish beds extensively outcrop in the territory surrounding the town of Nardò, in the Lecce Province. The ichthyolitiferous strata have been exploited from three main localities, Porto Selvaggio, Canale and Cava. All of them are easily accessible. Representatives of the actinopterygian orders Aspidorhynchiformes, Aulopiformes, Beryciformes, Characiformes, Clupeiformes, Elopiformes, Gasterosteiformes, Gonorhynchiformes, Ichthyodectiformes, Lampridiformes, Perciformes, Pycnodontiformes, Tetraodontiformes, and Zeiformes, as well as of some elasmobranchs have been found. The Nardò ichthyofauna certainly represents one of the most important and diverse Cretaceous fish assemblage of the Tethyan realm. This assemblage provides among the earliest representatives of several clades which dominates the marine environments today.Altamura: a significant cretacean dinosaur trackwaysThree distinct dinosaur track sites are presently known from the Apulian carbonate platform. The main one crops out in an abandoned quarry (ECOSPI quarry ) opened in the Altamura limestone (Turonian–Maastrichtian?) near the Altamura town (Bari). It includes thousands of medium-sized quadruped trackways ascribed to ornitischians. A single trackway and a few isolated footprints are the type material of A medium-sized hadrosaurid Apulosauripus federicianus.A single tridactyl footprint is tentatively referred to a theropod and one trackway “might pertain to a very small sauropod”. The age of the fossiliferous level is “Santonian, excluding the earliest part of this stage”Castro: the Oligocene coral reef complex of the Castro LimestoneThe coral reef complex of the Castro Limestone (lower Chattian) is extensively exposed along the eastern coast of the Salento Peninsula (Apulia), from the city of Otranto to S.M. di Leuca Cape. One of the best outcrops is located in close proximity to the entrance of the Zinzulusa cave (Castro Marina, Lecce). The coral fauna is characterized by a high diversity and about 20 different genera can be recognized. Together with corals, other common fossils are represented by coralline algae, larger (lepidocyclinids) and planktonic foraminifers, bivalves, gastropods and echinoids.The Castro Limestone represents a rare example of a fossil reef really comparable with present day coral reefs. The large suite of recognized and described reef features, the types of coral assemblages and interpretation of paleoenvironmental conditions can be used as a reliable reference model for understanding Cenozoic coral reef evolution. Lecce: the Miocene marine megavertebrates of the Pietra LecceseThe Burdigalian to Messinian fossiliferous biocalcarenites of the Pietra Leccese largely outcrop in the Salento peninsuls, most notably in the area surrounding the city of Lecce. The study of the fossils collected from the numerous productive sites located in the nearby of Lecce started in the XVI century, resulting in a huge amount of published articles and monographic papers. The characteristic fossil assemblage primarily consists of articulated skeletal remains of large marine vertebrates, including cetaceans, sirenians, chelonians, crocodiles, and teleostean fishes, and shark teeth, but mollusks, crustaceans, echinoids and brachiopods are also rather common. The fossil assemblage consists of a mixture of shallow water and oceanic taxa, and provides an excellent overview of the structure and composition of the Miocene megavertebrate communities of the Medterranean Basin.Apricena: the mammalian fossil association and the oldest European lithic industryThe site of Pirro Nord (also known as Cava Pirro or Cava dell’Erba) is known in literatur

2008 - Coralline Algae in Messinian (Upper Miocene) Mediterranean Reefs [Abstract in Atti di Convegno]
BRAGA J., C; Vescogni, Alessandro; Bosellini, Francesca; Aguirre, J.
abstract

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2008 - Estimating Mediterranean Oligocene-Miocene sea-surface temperature:an approach based on coral taxonomic richness [Articolo su rivista]
Bosellini, Francesca; Perrin, C.
abstract

During the Oligocene and Miocene, shallow-water carbonates of the Mediterranean region were rich in scleractinian coralsthriving within various depositional settings, including different reef types. Their diversity patterns, although related to a complexinterplay between a suite of environmental factors and palaeobiogeography, are considered to be strongly controlled by climatevariability and changes in sea-surface water temperature.By using the quantitative relationship between present-day coral taxonomic richness and prevailing sea-water temperature,underlined by the so-called “energy hypothesis”, we test zooxanthellate-coral generic richness values from a selection of 102Oligocene–Miocene localities of the Mediterranean region as a proxy for relative palaeotemperatures.For each Oligocene–Miocene stage, generic richness values per z-coral site are firstly examined, together with variations of theMediterranean z-coral generic pool. For better testing the method and assessing its potential application, patterns of generic richnessand inferred palaeotemperatures are then compared with global palaeoclimatic curves based on marine oxygen stable isotopes data orother climate proxies, such as palaeoclimatic records from European continental floras and from fossil coral linear extension rate.Results clearly show that fluctuations of coral richness-derived palaeotemperatures correspond relatively well with globalchanges of sea-water temperature especially for the entire Oligocene, the Chattian–Aquitanian boundary and the Late Miocene.The well known Mid-Miocene Climatic Optimum, however, is not recorded, suggesting that regional factors, acting together withimportant palaeogeographical changes, exerted a strong control on the generic richness of Mediterranean z-coral communities.A remarkable decline of taxonomic richness is recorded after the Burdigalian, togetherwith a gradual decrease of palaeotemperaturesin the region. From theMiddleMiocene onwards to theMessinian, however, an increase in the temperature range of z-coral localities isclearly visible, indicating that z-coral communities were able to thrive and adapt to a wider temperature range, as theMediterranean wasgradually migrating northwards, outside the tropical belt.The “energy hypothesis”, if used at global or regional scale, can be considered a promising and reliable method for estimatingCenozoic palaeotemperatures, from coral or other suitable fossil assemblages of shallow-water carbonates.

2008 - Estimating sea-surface palaeotemperatures from shallow-water carbonates: the example of Mediterranean Oligocene-Miocene corals. [Abstract in Rivista]
Bosellini, Francesca; Perrin, C.
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2008 - High salinity variability during the early Messinian revealed by stable isotope signatures from vermetid and Halimeda reefs of the Mediterranean region [Abstract in Atti di Convegno]
T. C., Brachert; Vescogni, Alessandro; Bosellini, Francesca; M., Reuter; R., MERTZ KRAUS
abstract

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2008 - Palaeoecological significance of vermetid reefs during the early Messinian of the Mediterranean Basin [Abstract in Atti di Convegno]
Vescogni, Alessandro; Bosellini, Francesca; Reuter, M; Brachert, T. C.
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2008 - Paving the way: accomplischments of the First Field Course on Coral Reef Biogeology held in the Red Sea (Marsa Alam, Egypt, 19-24 April 2009) [Abstract in Rivista]
Bosellini, Francesca; Morsilli, M.; Silvestri, Giulia; Taviani, M.
abstract

While it is a common practice for a number of academic organizations to organize field courses outside their national borders on tropical coral reef science for undergraduate and graduate students, the same does not equally holds true for the Italian academy. A first attempt to reverse this situation resulted in the organization and accomplishment of Field Course on Coral Reef Biogeology hold in the Red Sea in April 2009. Our call to enrol attendees was extremely well received resulting in over 60 submissions for participation exceeding the quota of 48 students set for this experience. Attendees proceeded from universities in Italy (Chieti, Ferrara, Modena, Padova, Pavia, Perugia, Napoli, Palermo) and Germany (Potsdam). The main target was undergraduate and graduate students. However, participants were not requested to document any particular background besides an average snorkelling capability although a basic background in geology, biology and natural sciences was preferable. The basic concept of the course was a holistic learning-through-doing approach to the geology, biology, and ecology of tropical coral reefs and other coastal environments, such as mangals. This field course was subdivided into two main phases. The first phase comprised field excursions at sea (reef snorkelling) and on land (outcrop) led by tutors to learn the basic environmental attributes of modern and Pleistocene coral reef complexes and coeval siliciclastic counterparts. The second phase was conducted by small groups and/or individuals to carry out original observations on selected aspects of coral reef biogeology with the scope to help students to design and carry out in the field a specific research project on their own. Basic results of these projects were briefly illustrated to all the participants in the evening.The area selected for the course is conveniently located along the Red Sea coast of Egypt at Abu Dabab bay, ca. 40 km north of Marsa Alam. The bay is easily accessible by foot from the quarters were the entire group was lodged during the course. The bay is unique in combining a well developed sandy bay rich in seagrass (providing food for a stable population of turtles and dugongs) with lush coral reefs entering from the open sea into the bay itself almost up to the shore. The site offers a fine example of fringing reefs, quite diverse in coral and fish populations, Excellent pre-modern coral reef terraces border the coastline at this same site (mainly MIS5e, last interglaciation) and expand into the interior for some hundred meters (middle-upper Pleistocene). The large wadi ending in Abu Dabab offered the opportunity to students to familarise themselves with arid environments and observe Tertiary syn-rift rocky sequences. The reconnaissance of modern coral reefs was supplemented by a boat trip to the Qu’lan islands, just offshore Hamata, ca. 100 km south of Marsa Alam. This facultative trip also permitted the exploration of Avicennia mangrove habitats nearby. The enthusiatic response offered by students is a clear signal of how they feel important such practical experiences for their formation and, consequently, the moral obligation of teachers to reiterate and further expand similar actions.

2008 - REEFCORAL: a database for assessing the spatio-temporal distribution of z-coral carbonate producers. [Abstract in Rivista]
Perrin, C.; Bosellini, Francesca
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2008 - REEFCORAL: an efficient tool for evaluating the taxonomic and palaeoecological evolution of z-coral communities in the Cenozoic Mediterranean realm [Articolo su rivista]
Bosellini, Francesca; Perrin, C.
abstract

Con lo scopo di valutare ed interpretare l’evoluzione delle comunità a coralli della regione mediterranea durante il Cenozoico, è stato recentemente messo a punto il REEFCORAL database. Attualmente il database contiene più di 3000 presenze di generi di coralli ottenuti da 285 località oligo-miocenichedi regioni circum-mediterranee (incluso l’attuale Bacino del Mediterraneo, la Paratetide, e alcune aree del Medio-Oriente ed europee affacciate sull’Atlantico). Attraverso i dati ottenuti dal database è stato possibile ricostruire le variazioni nella ricchezza dei generi per l’intera regione mediterranea durante l’Oligo-Miocene. Inoltre, applicando la relazione quantitativa che lega la ricchezza tassonomica dei coralli di scogliera attuali alla temperatura media annuale dell’acqua (evidenziata dalla cosiddetta “Energy Hypothesis”), i dati relativi a 102 località selezionate sono stati testati come strumento per la stima di paleotemperature.

2008 - Rhodalgal lithofacies of the Porto Badisco Calcarenite (upper Chattian, Salento, Apulia, southern Italy) [Abstract in Rivista]
Brandano, M.; Bosellini, Francesca; MATEU VICENS, G.; Morsilli, M.; Parente, M.; Vannucci, G.
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2008 - Turbid-water coral assembalges: a case study from the Oligocene Ligure-Piemontese Basin (N Italy). [Abstract in Rivista]
Silvestri, Giulia; Bosellini, Francesca; Morsilli, M.
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2008 - Turbid-water coral assemblages: a case study from the Oligocene Tertiary Piedmont Basin (N. Italy) [Articolo su rivista]
Silvestri, Giulia; Bosellini, Francesca; Morsilli, M.
abstract

Le biocostruzioni a coralli vengono tradizionalmente associate a contesti di acque tropicali poco profonde, ben illuminate ed oligotrofiche, in cui gli organismi realizzano impalcature di ragguardevole sviluppo verticale e notevole estensione. In realtà, numerosi esempi sia attuali che fossili testimoniano come la distribuzione delle faune a coralli non sia limitata a questo tipo di ambienti, bensì si realizzi anche in contesti di acque stabilmenteo occasionalmente torbide per via di un elevato apporto terrigeno.Nel record geologico sono numerose le biocostruzioni a coralli associate a sedimenti marnosi comprendenti una frazione silico-clastica (SANDERS & BARON-SZABO, 2005). Il Bacino Terziario Piemontese (Italia settentrionale) costituisce a questo proposito un interessante esempio. In questo dominio paleogeografico infatti si svilupparono durante l’Oligoceneassociazioni a coralli in ambienti di fan-delta e pro-delta in cui la sedimentazione eracaratterizzata da arenarie silico-clastiche e argille (PFISTER, 1980).La successione è caratterizzata dalla episodica produzione di abbondante rubble a coralli ramificati appartenenti ai generi Acropora e Stylophora. Queste facies sono state distinte sulla base di caratteristiche tessiturali e granulometriche, pattern deposizionali, tipo di biota, aspetti tafonomici (in particolare incrostazione e bioerosione). Tra le facies costituite da rubble sono state riconosciute: 1) un rudstone a Stylophora thirsifirmis; 2) un rudstone/floatstone in cui prevale Stylophora thirsifirmis; 3) un floatstone ad Acropora haidingeri.Nella successione si riscontra anche la presenza di livelli con colonie coralline in posizione di vita, appartenenti in prevalenza ai generi Caulastrea, Goniopora, Astreopora, Diploria, Favia, Antiguastrea. Esse mostrano modalità di crescità e caratteri morfologici tipici di coralli adattati ad ambienti ad elevatoapporto terrigeno. Questi coralli inoltre non formano una vera e propria biocostruzione, ma piuttosto piccole impalcature poco sviluppate in senso verticale. La biodiversità relativamente ridotta, se comparata connumerose altre associazioni a coralli dell’Oligocene, e il ridotto spessore di queste biocostruzioni, suggeriscono che l’apporto sedimentario, la scarsa luminositàed eventualmente episodi di elevata concentrazione di nutrienti costituivano per queste faune il maggiore fattore di controllo.

2008 - Vermetid reefs and their use as palaeobathymetric markers: new insights from the Late Miocene of the Mediterranean (Southern Italy, Crete) [Articolo su rivista]
Vescogni, Alessandro; Bosellini, Francesca; Reuter, M.; Brachert, T. C.
abstract

Vermetids are a poorly known family of reef-building gastropods characterized by an extremely irregular growthof the shell. Vermetid reefs are known from the Badenian (Middle Miocene) to present-day and their mainimportance is related to their use as sea-level indicators, strictly associated to the intertidal or immediate subtidalzone. During their evolution, two different vermetid genera have been recognized as reef-builders: Petaloconchuswas the major component of vermetid reefs until the Holocene when, for still unknown reasons, it was almostcompletely replaced by Dendropoma. In the Mediterranean Basin, Petaloconchus reefs have been frequently foundin close association to Late Miocene coral bioconstructions. New finding of Petaloconchus reefs within the slopefacies of the Salento Messinian reef complex (southern Italy), together with new data from late Tortonian–earlyMessinian reefs of Crete (Greece) provide further information on the palaeoecology of these peculiarbioconstructions. Stratigraphical and sedimentological contexts of Salento and Crete vermetid reefs have beendescribed, together with an account of their size, shape and inner structure. Biotic (vermetids, serpulids,bryozoans and coralline algae) and abiotic components (earlymarine cements and intra-reef sediment) have beenidentified by microfacies analysis, and their percentage-abundance has been reported. These data allow thedescription of vermetid reefs from two different depositional settings: along the shelf edge and, for the first time,within the coral reef slope. Shelf-edge and slope Petaloconchus reefs show the same inner structure andcomposition, but they differ by their shape, by the density of the framework, and by the relative proportion of theassociated reef-building organisms (serpulids, bryozoans and coralline algae). Additional information on theirpalaeobathymetric setting have been acquired from the presence of other reef-building biota (Porites corals andHalimeda green algae)which occur in close proximity to slope vermetid reefs, together with observations on someanatomical feature of Petaloconchus shells. Results clearly indicate for Petaloconchus reefs a palaeobathymetricrange spanning from the upper subtidal zone down to 30–50 m of depth. The present study confirms vermetidreefs as important tools for the reconstructions of ancient sea-level, but great attention has to be paid to theidentification of the main reef-building vermetid. Actually, while a great number of present-day Dendropomareefs can be associated to the mean sea-level, Late Miocene vermetid reefs from Salento and Crete indicate forPetaloconchus bioconstructions a wider palaeobathymetric range.

2007 - Early Messinian aragonite event reveals high salinity variability prior to the “Messinian Salinity Crisis” (Late Miocene) in the Mediterranean region. [Abstract in Rivista]
Brachert, T. C.; Bosellini, Francesca; Reuter, M.; Vescogni, Alessandro; MERTZ KRAUS, R.
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2007 - High salinity variability during the early Messinian revealed by stable isotope signatures from vermetid and Halimeda reefs of the Mediterranean region. [Articolo su rivista]
Brachert, T. C.; Bosellini, Francesca; Vescogni, Alessandro; Reuter, M.; Grimm, K. I.
abstract

The early Messinian deep-water record of the Mediterranean region reveals increasing evidenceof significant salinity stress prior to the Messinian Salinity Crisis (MSC). In shallow reef environments such apattern has not yet been documented, however, the paleoecological interpretation of some sedimentarycomponents, such as stromatolites in coral reef frameworks, has remained ambiguous. We present data from openand semi-restricted reef settings of southern Italy and Greece (Crete), where stable isotope analyses have beenmade on early marine carbonate cements from vermetid reefs and Halimeda bioherms. d18O compositions ofmarine cements translate into sea surface salinity (SSS) peaking at 50 to 60‰, certainly too high for most shallowwater biota (i.e. zooxanthellate corals). It seems, therefore, that recurrent events of high salinity have occurredcausing events of community replacement eventually ending up in “abiotic” episodes. These events, however, weretoo short to be recorded as discrete beds in 4th order depositional sequences. Because the cements reflecting highsalinity occur equally in the platform margin and reefal slope facies, salinity build-up was not linked to evaporativedraw-downs of sea level. Such a scenario fits concepts of the MSC starting synchronously over great part of theMediterranean as a deep brine pool.

2007 - Oligocene nearshore benthic assemblages and coral facies of the northern Gargano Promontory (southern Italy). [Abstract in Rivista]
Papazzoni, Cesare Andrea; Bosellini, Francesca; Morsilli, M.
abstract

Shallow water carbonate successions of Oligocene age are quite well distributed in the Apulia domain and are often associated with the development of luxuriant coral reef systems (Salento Peninsula, Maiella Mountain). The dominant biogenic components generally consist of rich associations of scleractinian corals and larger foraminifera.In the Gargano Promontory, the Oligocene has been recently reported for the first time and a new carbonate unit informally established and named as Grotta S.Michele limestone (Morsilli et al., 2005). The aim of the present study is thus to investigate the type locality of this unit in order to describe and interprete its lithologic composition and biotic content through facies analysis.The stratigraphic succession consists of grainstones-rudstones to wackestones-mudstones, reaches a maximum thickness of about 28 m and clearly shows a fining-upward trend.The fossil fauna is mainly characterized by abundant scleractinian corals, associated with benthic forams and coralline algae. Corals are represented by very few genera and basically consist of globose colonies of Goniopora near the base of the succession, followed by floatstones-rudstones rich in branched Acropora, Stylophora, Alveopora and phaceloid colonies of Caulastrea towards the top. Similarly, also the foraminiferal assemblages, dominated by miliolids and soritids, are rather poor, often with a small number of specimens and low taxonomic diversity. Some larger foraminifera such as Archaias, Austrotrillina, Nephrolepidina, and Nummulites also occur, thus indicating an Oligocene age (Chattian).Several facies types have been identified on the basis of macroscopic observations in the field and microfacies analysis. Data are provided in particular for the distribution and relative abundance of the main biotic components, including coralline algae, bivalve and gastropod fragments, together with textural features.The facies association suggests a nearshore, sheltered, shallow-water marine paleoenvironment with possible evidence of changes in hydrodynamic conditions from very low to moderate-high energy. Within this setting, the unusual low-diversified coral assemblages and the absence of a true framework can be interpreted as a response to stressed conditions probably controlled by the inherited paleotopography.ReferencesMorsilli, M., Noferini, M., Bosellini, A., Bosellini, F., Brandano, M., Furlanis, S., Gianolla P., Neri, C., Rusciadelli, G. & Russo, A., 2005, The Oligo-Miocene of the Gargano Promontory: new insights of the paleoenvironmental evolution of the Apulia domain (Southern Italy). ESF Workshop “Carbonate Systems during the Oligocene-Miocene climatic transition”, Potsdam (Germany), 22-25 February 2005, Abstract book.

2007 - Palaeoecological implications of coralline algal assemblages from a Messinian reef complex (Salento, southern Italy) [Abstract in Rivista]
Vescogni, Alessandro; Braga, J. C.; Bosellini, Francesca
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2007 - Rhodalgal lithofacies of the Porto Badisco Calcarenite (Upper Chattian, Apulia Italy). [Abstract in Rivista]
Brandano, M.; Vannucci, G.; Morsilli, M.; Bosellini, Francesca; MATEU VICENS, G.
abstract

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2006 - Biotic changes and their control on Oligocene-Miocene reefs: A case study from the Apulia Platforrn margin (southern Italy) [Articolo su rivista]
Bosellini, Francesca
abstract

The Oligocene-Miocene represents, for the Cenozoic, a period of extensive reef development and is characterized by a number of important changes influencing both carbonate-producing biota and architecture of reefs and carbonate platforms. The Mediterranean region, in particular, was characterized during this time by a complex palaeogeographic and climatic history with stepwise transition towards cooler conditions, biotic turnovers and the complete disappearance of zooxanthellate corals and reefs at the very end of the Miocene. A comparative study of two reef complexes that in different times (Chattian and Messinian) grew in the same physiographic and depositional setting, i.e. the stable, undeformed eastern margin of the Apulia Platform (eastern coast of the Salento Peninsula, southern Italy), highlights evolutionary, ecological and climatic changes that differentiate Oligocene and Late Miocene reef biota of the region. In particular, the study illustrates how different reef biotic assemblages can produce different reef types, frameworks and growth fabrics along reef tracts and reef slopes. The Chattian reef is characterized by a homogeneous reef-building biota, being largely dominated by a high diversity and abundant coral fauna associated with a moderate presence of coralline algae, and thus forming a single reef type. In contrast, the Messinian reef shows a very low coral diversity but several other reef-building components with abundant and varied secondary reef builders (coralline algae, Halimeda, encrusting foraminifera, bryozoans, serpulids and microbial associations). The reef, therefore, is characterized by a heterogeneous reef-building biota that forms different frameworks and growth fabrics. The feedback to the environment of this different biotic composition is very evident in the two reefs and especially in the slope. During the Chattian a slope, mainly consisting of gravity-displaced debris, resulted from the abundant production of reef rubble, associated with a relatively poor framebuilding capacity. Conversely, during the Messinian, a biologically stabilized slope resulted from proliferation of a variety of binding organisms that strongly colonized the substrate. The climatic cooling which occurred during the Miocene may be considered the main controlling factor of the diversity turnovers and changes that affected the coral fauna, but other environmental factors, such as changes in nutrient regimes and in hydrodynamic conditions of the sea associated with the emerging Apennine chain, may have played a role in determining differences in the reef biota and in the reef facies. (c) 2006 Elsevier B.V. All rights reserved.

2006 - Ca isotope fractionation of inorganic, biologically induced and biologically controlled calcium carbonates. [Abstract in Rivista]
Böhm, F.; Gussone, N.; Eisenhauer, A.; Reynaud, S.; Paytan, A.; Bosellini, Francesca; Brachert, T.; Reitner, J.; Wörheide, G.; Dullo, W. C.
abstract

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2005 - The Neogene carbonate succession of the Gargano Promontory (Apulia, Southern Italy). [Abstract in Rivista]
Morsilli, M.; Noferini, M.; Bosellini, Francesca; Brandano, M.; Gianolla, P.
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2003 - A Messinian reef at the northern limit of the Mediterranean coral reef zone (Northern Apennines, Italy). [Abstract in Atti di Convegno]
Vescogni, Alessandro; Bosellini, Francesca; Russo, Antonio
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2003 - Ciottoli e blocchi di origine recifale nei conglomerati basali della Formazione a Colombacci (Messiniano, bassa Val Secchia, Appennino settentrionale) [Articolo su rivista]
Bosellini, Francesca; Panini, Filippo; Vescogni, Alessandro
abstract

Recent erosion in the lower valley of the Secchia River has uncovered part of the late Messinian and Pliocene succession, which consists of the Colombacci and Argille Azzurre formations, respectively. A conglomerate unit, about twenty meters thick and discordant on the underlying epi-Ligurian substratum, occurs at the base of the Colombacci Formation. This conglomerate holds carbonate cobbles and boulders of reefal origin. A detailed analysis of these carbonate clasts allowed to recognize some typical microfacies (bioclastic rudstone, coral packstone, algal crust wackestone, mudstone-wackestone rich in bryozoans and serpulids), which suggest a correlation with the lower Messinian reefal deposits outcropping in several circum-Mediterranean localities. At present, lower Messinian deposits characterized by similar reefal facies do not occur in the Apennines of Modena and Reggio provinces; the only outcrops of Messinian reefal carbonates located on the Po plain side of the Apenninic chain occur in the Parma-Piacenza foothill area (Vigoleno, Scipione). The large size and the sedimentological characters (alluvial and fan-delta environments) of the conglomerate suggest that the provenace of the carbonate clasts was the present-day sector of the Modenese Apennines and that the original reefal deposits were completely eroded during a relative short time, i.e. between the late Messinian and the Early Pliocene. These reefal sediments, likewise those of northwestern Emilia, most probably constituted the basal unit of the Messinian depositional sequence which includes also the pre-evaporite and evaporite deposits. The reefal carbonates of the Modena Apennines, together with those of northwestern Emilia and Monferrato, represent the northern boundary of the Messinian coral reefs distribution. Their occurrence at these latitudes may correspond to a particular warm period which, according to isotope and radiometric data from oceanic sediments, should be placed between 6.4 and 6.2 Ma ago.

2003 - Encrusting foraminiferan assemblages as palaeoecological tools in reef environments. A case from the Late Eocene of northern Italy [Abstract in Atti di Convegno]
Papazzoni, Cesare Andrea; Bosellini, Francesca
abstract

Coral-encrusting foraminiferan associations and their variations along a palaeobathymetric gradient represented by the different facies that characterize the shallowing upward parasequences of the Nago Limestone (Upper Eocene, Trentino, northern Italy) have been investigated. From a relatively deep reef slope up to the shallow shelf-edge, corals have been recognized to be encrusted by different types of foraminiferan assemblages that change in composition and distribution and differ on the basis of relative abundance of species, growth form and type of encrusted coral surface. Three main assemblages have been recognized and named according to the dominant and statistically significant taxa: 1) Miniacina aff. multiformis assemblage (Facies 1: reef slope); 2) Acervulina-Fabiania-Haddonia assemblage (Facies 2: mid-depth reef slope); and 3) Solenomeris-Carpenteria assemblage (Facies 3: shallow reef front). The succession of encrusting foraminiferan assemblages is interpreted as controlled mainly by light, competition with coralline algae, hydrodynamic energy, and coral growth fabric, suggesting that these organisms can be used as ecological tools in palaeoenvironmental reconstructions of ancient reefs. Foraminiferans encrusting corals directly (not associated with algal crusts) mostly occur in cryptic habitats and especially on coral lower surfaces, whereas on exposed surfaces they generally contribute to form crusts together with coralline algae. These foralgal crusts preferentially develop along the mid-depth reef slope (Facies 2), on both upper and lower surfaces of the platy corals. Test morphology, and especially the flat vs. globose morphotypes ratio, positively correlates with increasing water energy across the shallowing upward sequence. However, within this general trend, their preferential encrusted surface is mainly controlled by light and consequent competition with coralline algae. Flat specimens mostly encrust coral lower surfaces where low light levels generally reduce competition for space with coralline algae. In contrast, globose morphotypes are successful on coral upper surfaces, where lateral spatial competition with algae is higher. The dense coral growth fabric that characterizes the shallower portion of the Nago reef front (Facies 3), provided cryptic habitats for the development of an encrusting foraminiferan assemblage partly similar to the one recognized within the relatively deep and poorly illuminated reef slope (Facies 1).

2003 - Palaeoecological significance of coral-encrusting foraminifera associations. A case study from the late Eocene of the Nago Limestone (Northern Italy) [Articolo su rivista]
Bosellini, Francesca; Papazzoni, C. A.
abstract

Encrusting foraminiferans, although representing an important component of the so-called cryptic assemblages in both modern and ancient reef environments, are in general poorly described and little is known as regards their association with corals. In this paper, we describe coral-encrusting foraminiferan associations in the different facies that characterize the shallowing upward parasequences of the Nago Limestone (Upper Eocene, Trentino, northern Italy). From a relatively deep reef slope up to the shallow shelf-edge, corals have been recognized to be encrusted by different types of foraminiferan assemblages that differ on the basis of relative abundance of species, growth form and type of encrusted coral surface. The succession of encrusting foraminiferan assemblages is interpreted as controlled mainly by light, competition with coralline algae, hydrodynamic energy, and coral growth fabric.

2003 - The changing biotic composition and its control on the nature of reef tracts and reef slopes: a case from the Oligo-Miocene of the Apulia Platform margin (Southern Italy). [Abstract in Atti di Convegno]
Bosellini, Francesca; Russo, Antonio; Vescogni, Alessandro
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2002 - Platy coral assemblages: 200 million years of functional stability in response to the limiting effects of light and turbidity. [Relazione in Atti di Convegno]
Rosen, B. R.; Aillud, G. S.; Bosellini, Francesca; Clack, N. J.; Insalaco, E.; Valldeperas, F. X.; Wilson, M. E. J.
abstract

Ecological assemblages of platy corals occurthrough most of the geological record of the Scleractinia(late Triassic to Recent) but they have received almost nodetailed attention. Recent studies have suggested that theyrepresent a photoadaptive response by photosymbioticcorals to reduced illumination in deeper and/or moreturbid waters. As an informal working group, we haveaimed to establish (1) if this model applies more generallyto the geological record, and (2) if so, what implicationsthis may have for long-term stability of tropical marineecosystems (e.g. role of photosymbiosis). Here we discusspreliminary results compiled from our own independentprojects in 32 study areas ranging from late Jurassic tomid Miocene age. We set out simple descriptive conceptsof platy corals and platy coral assemblages and provideother palaeoecological and geological information thatcharacterises these assemblages. Sedimentological andpalaeoecological evidence supports the photoadaptivenature of platy coral assemblages ('euphotic floor model'),and indicates their ecological functional stability since thelate Triassic. We recognise seven variants of suchassemblages according to the role of turbidity in differentspatiotemporal settings. Preliminary work so far has failedto reveal closely comparable modern analogues.

2002 - Quando i dinosauri avevano le piume - I fossili cinesi dell'area di Benxi [Altro]
Dalla Vecchia, F. M.; Bosellini, Francesca; Ferretti, Annalisa; Papazzoni, Cesare Andrea; Serventi, Paolo; Vescogni, Alessandro; Corradini, Elena
abstract

Pubblicazione divulgativa in occasione di esposizione temporanea.

2002 - The Messinian reef complex of the Salento Peninsula (Southern Italy): Stratigraphy, facies and paleoenvironmental interpretation [Articolo su rivista]
Bosellini, Francesca; Russo, Antonio; Vescogni, Alessandro
abstract

An integrated study of the early Messinian reef complex cropping out along the eastern coast of the Salento Peninsula (southern Italy), including stratigraphy, facies analysis and paleoecological aspects, is here presented. Fourteen facies types belonging to three main facies associations (back reef and shelf, shelf-edge, slope) have been recognized. They document a wide spectrum of depositional environments, reef building organisms and growth fabrics, in response to depth and other environmental factors in different parts of the reef complex. The biotic structure of the reef is also described and discussed in detail. It consists of different types of reef building organisms and of their bioconstructions (mainly Porites coral reefs, Halimeda bioherms and vermetidmicrobial trottoirs), that differ in composition and structure according to their position on the shelf edge-to-slope profile. Results indicate that the reef complex of the Salento Peninsula has strong similarities with the typical early Messinian reefs of the Mediterranean region. However, the recognition of some peculiar features, i.e. the remarkable occurrence of Halimeda bioherms and of vermetid-microbial trottoirs, gives new insights for better understanding reef patterns and development of the reef belt during the Late Miocene in the Mediterranean.

2001 - Messinian reef-building assemblages of the Salento Peninsula (southern Italy): palaeobathymetric and palaeoclimatic significance [Articolo su rivista]
Bosellini, Francesca; Russo, Antonio; Vescogni, Alessandro
abstract

This paper mainly addresses the description and interpretation of different reef-building assemblages recognised within an early Messinian reef complex recently discovered along the eastern margin of the Apulia Platform (Salento Peninsula, southern Italy), It is the first Late Miocene reef recorded for the 'Adriatic region' and its location partly changes boundaries of coral reef distribution during this time in the Mediterranean. The Messinian reef complex (Novaglie Formation) is interpreted as a succession of fringing reefs accommodated in palaco-reentrances or palaeoembayments of the original Messinian rocky shore and overlying discordantly the underlying Cretaceous to Oligocene units. It consists of a discontinuous reef tract and associated clinostratified fore-reef slope. Relatively precise dating of the reef complex has been achieved using benthic foraminifera and ostracods associations. Three main different reef-building assemblages have been recognised: (1) Halimeda bioherms (2) Porites reef and (3) vermetid-microbial 'trottoirs'. Each assemblage is described in detail according to its architecture and structure (setting, shape, quantitative estimation of the framework density), biotic components (taxonomic composition and relative abundance of the reef-builders, growth form, associated fauna), and intra-reef sediment (texture and fabric). Palaeoecologic analysis, based on physical observation within the margin-slope of the reef complex and in comparison with present-day analogues and their ecological demands, indicates that distribution and vertical succession of the three different reef assemblages are strictly depth-related, suggesting an ecological replacement consequent on small relative sea-level changes (fourth order), closely comparable with those already indicated for the early Messinian. Special attention is given to the remarkable abundance of vermetids that, together with microbial crusts, formed scattered 'trottoirs' along the shoreline. Vermetid occurrences have been extensively cited in the literature for the Late Miocene of the Mediterranean but poorly studied in detail. Here, their palaeoecologic significance is emphasised, indicating that these organisms can be used as reliable palacobathymetric and palaeoclimatic indicators. Regarding the Miocene of the Mediterranean. development of vermetid-microbial 'reefs', so far recorded for the Messinian, is preferentially associated with low-diversity coral reefs and is interpreted as being mainly controlled by climatic constraints. (C) 2001 Elsevier Science B.V. All rights reserved.

2000 - Importanza paleobatimetrica e paleoclimatica delle biocostruzioni a vermetidi nel Miocene Superiore della Penisola Salentina (Italia meridionale). [Abstract in Atti di Convegno]
Vescogni, Alessandro; Bosellini, Francesca; Russo, Antonio
abstract

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1999 - Significance of Porites - Halimeda and vermetid assemblages. An example from a Messinian reef of the Salento Peninsula (southern Italy). [Abstract in Atti di Convegno]
Bosellini, Francesca; Russo, Antonio; Vescogni, Alessandro
abstract

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1999 - Stratigraphic architecture of the Salento Coast from Capo d’Otranto to S.Maria di Leuca (Apulia, Southern Italy) [Articolo su rivista]
A., Bosellini; Bosellini, Francesca; Ml, Colalongo; M., Parente; Russo, Antonio; Vescogni, Alessandro
abstract

The Cretaceous to Quaternary succession of the Apulia Platform cropping out on the eastern coast of the Salento Peninsula shows a special stratigraphic architecture. Whereas on the platform top, i.e. on the Salento Peninsula proper, the succession is at most a few tens of metres thick and is punctuated by unconformities, on the margin and slope of the platform, along the present-day eastern coast of the peninsula, several carbonate systems are laterally disposed and grafted one upon the other. Three of these systems are clinostratified and include well developed reef tracts of Priabonian, early Chattian and early Messinian age.The geologic conclusion of our study is that, since the Late Cretaceous, the eastern coast of the Salento Peninsula grossly coincided with the margin of the Apulia Platform. This paleogeographic element acted as a foreland horst and registered important geodynamic events related to the growth of the adjacent Hellenide and Apennine thrust belts. During the last 60 m.y., the horst carapace was constantly near sea level and sediments were mainly accommodated and preserved on the deep margin and slope of the platform.

1999 - The scleractinian genus Hydnophora (revision of Tertiary species). [Articolo su rivista]
Bosellini, Francesca
abstract

This report presents a systematic revision of the Tertiary species of the common reef-building coral Hydnophora. Major diagnostic characters of the various Tertiary genera that have been commonly confused with Hydnophora (Leptoria, Monticulastraea, Staminocoenia, Michelottiphyllia and Angeliphyllia) are defined and subsequently compared in order to establish differences and synonymies. With the exception of Leptoria, all other genera are considered synonyms of Hydnophora. The forty-five Tertiary species ascribed to Hydnophora, or to synonymous genera, have been revised and type material analyzed. Collected material from Oligocene Italian localities and Miocene localities from Somalia and Pakistan has been also analyzed in order to provide a consistent taxonomy for distinguishing species within the genus, especially for the Mediterranean Tertiary. According to this report, of the forty-five species of Hydnophora previously described, only twenty-one appear to be distinct. The Tertiary distribution of the genus, which started in the Late Paleocene, clearly shows that species richness increased significantly from Paleocene to Miocene. Originations of species were mostly concentrated during two time intervals, respectively the Chattian for the Mediterranean and the Burdigalian for Eastern Tethys. As regards the Mediterranean, the genus developed only during Chattian time with five fully described species. The genus became extinct in both Caribbean and western-central Mediterranean regions at the end of the Oligocene and subsequently developed in eastern Tethys regions during the Miocene. A new name is proposed for the only Paleocene species: Hydnophora gregoryi.

1998 - Diversity, composition and structure of Late Eocene shelf-edge coral associations (Nago Limestone, Northern Italy) [Articolo su rivista]
Bosellini, Francesca
abstract

During the Late Eocene, shelf-edge patch reefs developed on the western margin of the Lessini Shelf. The coral fauna, studied in the Nago Limestone type locality, is described and interpreted for the first time, and provides further data for better understanding of the generally poorly known Eocene reef communities. Facies analysis was carried out across the shallowing upward succession that characterizes the well exposed type-section of the Nago Limestone. Four distinct facies are identified and a detailed qualitative-quantitative investigation has been applied to the coral-bearing facies in particular, in order to describe and quantify the distribution and palaeoecological zonation of corals. By a comparison of sedimentological and palaeoecological data, it is possible to reconstruct a depositional model of the Nago Limestone at its type locality. In particular, the palaeoecological study clearly reveals that corals change with depth in taxonomic composition, in percentage and proportion within the framework and in growth form, allowing the definition of a relative depth coral zonation. Three coral associations are recognized from the base to the top of the shallowing upward sequence. These differ from each other in the relative abundance of main reef-builders, in the growth form exhibited by corals in growth position and in the density of the reef framework. These variations are interpreted as responses to major environmental controls which prevailed during the deposition of the different facies (mainly light intensity and hydrodynamic energy). The coral species Actinacis rollei REUSS is the most abundant and ubiquitous coral of the Nago Limestone. Its adaptation to low-light levels is described here for the first time, confirming the high plasticity of this important Paleogene reef-builder. The results of the present study are finally compared with data from other Middle-Late Eocene European reef sites and some common features are inferred.

1996 - Autoecological significance of growth form in the scleractinian coral Actinacis rollei Reuss (Oligocene, Lessini Mountains, Northern Italy). In Cherchi A. (ed.). Autoecology of selected fossil organisms: Achievements and Problems. [Articolo su rivista]
Bosellini, Francesca; Stemann, T. A.
abstract

The scleractinian coral Actinacis is an important component of reef communities from the Oligocene Lessini Shelf of Northern Italy. Actinacis occurs as massive-laminar colonies or thin to thickly branched thickets. In the present study we have used a combination od discriminant analysis and principal component analysis of corallite measurements to show that these two distinct growth forms cannot be distinguished on the basis of corallite characteristics. Thus, the two growth forms represent a single species, A.rollei, with a colony shape that varied as an autoecological response to the differeing environmental conditions that prevailed during deposition of the two facies.

1996 - Systematics of the Oligocene to Miocene reef coral Tarbellastraea in the northern Mediterranean [Articolo su rivista]
Af, Budd; Bosellini, Francesca; Ta, Stemann
abstract

Multivariate statistical analyses are used to distinguish species of the common reef-building coral Tarbellastraea at Oligocene and Miocene localities within the Aquitaine Basin, western Mediterranean, and central Paratethys regions; and to trace their distributions through geological time. Thirteen measurements or counts are made on thin sections of 126 colonies collected at 13 widely scattered localities, whose geological ages are newly updated. The data are analysed using average linkage cluster analysis and canonical discriminant analysis to distinguish clusters of colonies representing morphometric species. Names are assigned by qualitatively comparing measurements on the statistically recognized species with those of primary types of all previously described species of Tarbellastraea. The results show that Tarbellastraea originated during the Oligocene (Rupelian) and became extinct during the Early Messinian. A total of 12 species (including two new species from the Italian Oligocene, and two species described previously as varieties) lived in the investigated areas during Oligocene and Miocene time. Except during the Oligocene, all but one species (T. ellisiana) were widespread. Although species richness within the genus remained constant at 5-7 species throughout much of its stratigraphical range, morphological disparity decreased significantly through time. The observed constancy in richness contrasts with the decrease reported overall in the Mediterranean reef coral fauna. Species originations were highest during the Burdigalian, when temperatures across the region increased. Species extinctions remained constant until the latest Miocene, when the extinction rate increased as cold Atlantic waters entered the Mediterranean. New species described are Tarbellastraea bragai, T. chevalieri, T. russoi and T. salentinensis.

1995 - The Scleractinian genus Actinacis. Systematic revision and stratigraphic record of the Tertiary species with special regard to Italian occurrences. [Articolo su rivista]
Bosellini, Francesca; Russo, A.
abstract

Twenty-seven Tertiary species belonging to the cosmopolitan reef-building scleractinian genus Actinacis, have been described in the literature. A detailed systematic revision has been carried out for Italian and European species by thin section measurements. A combination of several measured corallite morphologic characters and diagnostic features is proposed as a realiable tool for species recognition. Preliminary examination of the stratigraphic and geographic distribution of Actinacis species suggests that: 1) the Tertiary distribution of the genus ranges from the Late Paleocene to the Late Oligocene; 2) the highest species diversity occrred during the Middle Eocene, when the genus consisted of a relatively large number of geographically restricted species; 3) only two widespread species survived the Eocene/Oligocene turnover and reached the Late Oligocene, when the genus became globally extinct.

1994 - Coral facies across an Oligocene fringing reef (Salento Peninsula, Southern Italy). [Relazione in Atti di Convegno]
Bosellini, Francesca; A., Russo
abstract

A well exposed Middle Chattian fringing reef complex outcropping for at least 40 km along the coastline of the Salento Peninsula (Southern Italy) is here described, contributing to a better knowledge of the evolution of Oligocene reefs in Italy and in the Mediterranean area. The fringing reef complex is represented by the Castro Limestone, an unconformity-bounded depositional sequence mantling a tectonically deformed "falaise" of Cretaceous-Eocene rocks. Stratigraphic and sediemntological features, together with paleontological characters, allow recognition of a virtually complete range of reef tract environments. Different geomorphic zones and associated coral facies, from "back reef" to fore reef, are here described.

1994 - The coral fauna of Vitigliano: qualitative and quantitative analysis in a back reef environment (Castro Limestone, Late Oligocene, Salento Peninsula, Southern Italy) [Articolo su rivista]
Bosellini, Francesca; Perrin, C.
abstract

The Castro Limestone, Middle Chattian in age, consists of various reef facies and has been described as a fringing reef complex. The reef facies outcropping near Vitigliano and the associated coral fauna, which have been previously interpreted to be part of a back-reef subenvironment, are here defined both qualitatively and quantitatively. Three main quantitative methods have been used for the characterization of the back reef facies: 1) counts of coral colonies on a subvertical measured surface, 2) line-transects, 3) quadrats. The results obtained from the various quantitative methods are compared and discussed. Moreover the coral density has been quantified from both linear and areal measurements and has been evaluated to be around 20%. However, corals occur as scattered colonies and do not form a true framework.

1993 - Organismi costruttori e ambiente di scogliera [Capitolo/Saggio]
Bosellini, Francesca
abstract

Si tratta di una introduzione alla paleoecologia dell'ambiente di scogliera con definizioni ed aspetti caratteristici delle scogliere coralline attuali, con una finestra sull scogliere del record geologico.

1992 - Coral facies and cyclicity in the Castelgomberto Limestone (Early Oligocene, Eastern Lessini Mountains, Northern Italy). [Articolo su rivista]
Bosellini, Francesca; Trevisani, E.
abstract

The Castelgomberto Limestone is a 200 m thick unit of Early Oligocene age (Rupelian) outcropping in the eastern Lessini Mountains (Southern Alps of Northern Italy). The internal cyclic organization of this Oligocene unit is described and analyzed on the basis of four selected sections; about 13 well-bedded grainstone units alternate with marly horizons rich in corals. This peculiar cyclicity is here interpreted as a response to variations in platform hydrodynamics, i.e. to smaller eustatic fluctuations affecting the Lessini Shelf reef-lagoonal complex. During highstand periods, the shelf was open and relatively deep (20-50m), and tidal currents and periodic storms were able to distribute bioclastic sands. During lowstands the shelf was more protected by the occurrence of marginal reefs and was colonized by patches of poritid corals, mainly branching. Moreover, the largely exposed northern areas supplied fine detritus to the shelf itself.

1992 - Rhaetian strata, Wombat Plateau: analysis of fossil communities as a key to paleoenvironmental change [Capitolo/Saggio]
M., Sarti; A., Russo; Bosellini, Francesca
abstract

Rhaetian fossil reef was penetrated on the Wombat Plateau. A study of fossil populations and associated sediment types showed a vertical transition from a sponge-dominated to a coral-dominated community, with associated hydrozoans-tabulozoans. The first colonization of the mobile ground was undertaken by sponges, whereas the coral community assemblage constituted the main core of a pinnacle reef complex, dominated by Retiophyllia in the lower part and by Astreomorpha associations upward. This change in fossil communities reflected shallowing of the environment of deposition. The density of frame-building organisms at Site 764, the fossil community organization, and the geometry and spatial arrangement of the organic buildups, as reconstructed by the seismic-reflection profiles, are all instrumental in defining the Rhaetian pinnacle assemblage offshore the Exmouth Plateau as a low-energy, bank-margin "reef complex'.

1992 - The Castro Limestone: stratigraphy anf facies of an Oligocene fringing reef (Salento Peninsula, Southern Italy). [Articolo su rivista]
Bosellini, Francesca; A., Russo
abstract

The coastline of the Salento Peninsula (Apulia region, Southern Italy) is characterized by a rocky shore with spectacular cliffs where the investigated fringing reef complex, the so called Castro Limestone, spectacularly outcrops for at least 40 km.As reconstructed from several measured sections, the Castro Limestone, which is Middle Chattian in age from our own data, disconformably mantles a tectonically deformed falaise of Cretaceous-Eocene rocks and is overlain by a remarkable erosional surface characterized by a very peculiar rhodolite rudstone. The Castro Limestone unit can be considered as a classic unconformity bounded depositional sequence representing, most probably, a shelf margin prograding complex, related to the major Middle Oligocene sea level lowstand.Stratigraphic and sedimentologic features, together with paleontological characters, allow recognition of a virtually complete range of reef environments across the reef profile.Several geomorphic zones and associated facies are described, from the most landward reef area (‘back reef’) across the reef flat and reef from downward to the fore reef slope, contributing to a better knowledge of the evolution of Oligocene reefs and reef communities in Italy and in the Mediterranean area.

1990 - Paleoenvironmental analysis and cyclicity of the Mustahil Formation (Cretaceous of Central Somalia) [Articolo su rivista]
A., Russo; Bosellini, Francesca; C. M., Mohamed; S. M., Yusuf
abstract

A Mustahil section, measured at Bur Bitthale near Belet Uen (Central Somalia), is here described. The succession, dated as Late Aptian to Early-Middle Albian age on the basis of good faunal evidence consists of two well developed thickening-coarsening sequences, where four different facies have been recognized. The cap of both sequences is represented by a rudistid framework dominated by Eoradiolites lyratus. We interpret these cycles as shoaling up parasequences, which are the result of two depositional regressions produced by the progradation of broad shallow-water carbonate systems over the adjacent ramp and deep shelf. -from Authors

1988 - Emendamenti alla stratigrafia paleogenica del Monte Baldo (Alpi meridionali, Italia) [Articolo su rivista]
Bosellini, Francesca; V., Luciani; A., Russo; A., Sirotti
abstract

The Monte delle Erbe Limestone, formally defined as an Early Oligocene formation of the Monte Baldo area, and considered laterally equivalent to the Acquenere Formation, is in fact of Late Eocene (Priabonian) age. It is therefore equivalent to the Nago Limestone and stratigraphically underlying the Early Oligocene succession which is constituted by a lower pelagic unit (Bolognano Marls) and an upper shallow-water terrigenous-carbonate sequence, the Acquenere Formation proper.

1988 - Oligocene corals from Monte Bastia (Vicentin Lessini Mountains, N.Italy) [Articolo su rivista]
Bosellini, Francesca
abstract

This study describes and illustrates 20 species of Oligocene corals from a new excavation near the top of Monte Bastia, close to the town of Montecchio Maggiore (Vicenza). As described by Bosellini & Russo (1988), 3 different Oligocene coral communities can be recognized in the Lessini Shelf. The coral fauna here presented belongs to the high species diversity community, typical of the Late Rupelian, or at least to the top of the average species diversity community

1988 - The Oligocene Actinacis coral community of the Southern Alps (Italy): temperature vs. terrigenous control. [Relazione in Atti di Convegno]
Bosellini, Francesca; A., Russo
abstract

Examination of the classic Oligocene coral reefs of the Vicentin (Southern Alps, Northern Italy), reveals a low specific diversity community dominated by Actinacis rollei Reuss. In the lower part of the Oligocene succession, above the Eocene-Oligocene boundary, A. rollei can be sporadically associated with few other species. Increasing species diversity occurs at the end of the Rupelian, where the succession is terminated. As a dramatic lowering of sea-water temperature is documented at the Eocene-Oligocene boundary, we interpret the Actinacis "explosion" in the Early Oligocene mainly as a hypothermic effect. The increasing coral species diversity during the Rupelian may then be a response to ameliorating sea-water temperature.