Annalisa FERRETTI - personale UniMoRe

Nuova ricerca

Annalisa FERRETTI

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

Home | Curriculum(pdf) | Didattica |

Pubblicazioni

2024 - The origin and significance of euhedral apatite crystals on conodonts [Articolo su rivista]
Malferrari, D.; Ferretti, A.; Medici, L.
abstract

Crystal overgrowth on fossil remains is well-documented in the literature. Attention has specifically focused on bioapatite (i.e., an apatite of biochemical origin regardless of post-mortem changes) configurations, in order to decipher any possible relation to fossilization/diagenesis. This study investigates the Rare Earth Element (REE) and other High-Field-Strength Element (HFSE) composition of euhedral crystals formed on the surface of conodont elements compared with that of crystal-free surfaces. Euhedral crystals are by definition crystals characterized by sharp faces, developing solids that, for apatite, assume the form of hexagonal prisms, reflecting its crystal symmetry. Late Ordovician (Amorphognathus ordovicicus Zone) conodonts from two localities in Sardinia and the Carnic Alps (Italy) are herein investigated. Conodont elements reveal the occurrence of smooth surfaces and surfaces partially covered with euhedral crystals. Since euhedral crystals did not reasonably grow during the organism’s lifetime, the REE and HFSE analysis can provide important insights into the crystal growth process. The experimental results indicated a substantial contribution of diagenetic imprinting for all the analyzed material, although more evident on euhedral crystals that are significantly enriched in middle and, subordinately, in heavy REE with respect to smooth surfaces. The positive correlations between La + Th vs log[ΣREE] and Ce + Th vs log[ΣREE] could support the hypothesis that the neoformed euhedral crystals grew also by depleting the pristine bioapatite of the conodont elements. Nevertheless, the occurrence of two types of apatite cannot be ruled out: euhedral crystals as neoformed products of diagenetic processes and smooth surfaces as remains of the pristine conodont bioapatite after diagenesis.

2023 - La Vita immobile in una Terra in movimento. Le Lezioni di Fisica Terrestre di Angelo Secchi (1879) [Capitolo/Saggio]
Vezzani, F.; Bertacchini, M.; Ferretti, A.
abstract

2023 - The earliest evidence of deep-sea vertebrates [Articolo su rivista]
Baucon, Andrea; Ferretti, Annalisa; Fioroni, Chiara; Pandolfi, Luca; Serpagli, Enrico; Piccinini, Armando; de Carvalho, Carlos Neto; Cachão, Mário; Linley, Thomas; Muñiz, Fernando; Belaústegui, Zain; Jamieson, Alan; Lo Russo, Girolamo; Guerrini, Filippo; Ferrando, Sara; Priede, Imants
abstract

: Vertebrate macroevolution has been punctuated by fundamental habitat transitions from shallow marine origins to terrestrial, freshwater, and aerial environments. Invasion of the deep sea is a less well-known ecological shift because of low fossilization potential and continual loss of abyssal fossil record by ocean floor subduction. Therefore, there has been a lack of convincing evidence of bottom-living vertebrates from pre-Paleogene deep seas. Here, we describe trace fossils from abyssal plain turbidites of the Tethys Ocean, which, combined with nannofossil dating, indicate that fishes have occupied the deep seafloor since at least the Early Cretaceous (Hauterivian-Barremian). These structures are identical to those produced by modern demersal fishes that feed by either scratching the substrate or expose their prey by water flow generated by suction or jetting. The trace fossils suggest activity of at least three fish species exploiting a productive abyssal invertebrate sediment fauna. These observations are consistent with Early Cretaceous vertebrate transition to the deep sea triggered by the availability of new food sources. Our results anticipate the appearance of deep-seafloor fishes in the fossil record by over 80 My while reassessing the mode of vertebrate colonization of the deep sea.

2023 - To be or not to be a conodont. The controversial story of Pseudooneotodus and Eurytholia [Articolo su rivista]
Ferretti, A.; Corradini, C.; Fakir, S.; Malferrari, D.; Medici, L.
abstract

The genus Pseudooneotodus (Drygant, 1974) is a genus of small and conical elements widely distributed from the Middle Ordovician to the Early Devonian throughout the world. Because of its unusual shape, Pseudooneotodus has long been considered enigmatic, and only in the late nineties of the last century the genus has been finally placed within conodonts according to histological data. This study investigates possible similarities between Pseudooneotodus and Eurytholia (Sutton et al., 2001), an incertae sedis genus of enigmatic plates with a phosphate composition. An association of over one hundred specimens of Pseudooneotodus beckmanni and Eurytholia bohemica was analyzed from conodont residues in two distinct geographical areas: the Prague Basin (Požáry and Mušlovka sections, Bohemia, Czech Republic) and the Carnic Alps (Rauchkofel Boden section, Austria). Through an investigation that combines the use of optical and electron microscopy (including focused ion beam scanning electron microscopy), X-ray microdiffraction, and trace element (HFSE) analysis by mass spectrometry, differences between these fossil groups were observed and compared with data resulting from typical conodonts (Dapsilodus obliquicostatus, Panderodus unicostatus and Wurmiella excavata) recovered from the same samples.

2022 - Middle-Upper Ordovician conodonts from the Ffairfach and Golden Grove groups in South Wales, United Kingdom [Articolo su rivista]
Ferretti, A.; Bergstrom, S. M.
abstract

The conodont fauna of the reference succession of the regional British Llandeilian Stage of the Llanvirn Series was first described in a classical study by Rhodes more than 65 years ago using single element (form) taxonomy. Although several subsequent authors have recorded a substantial number of conodont taxa from the Llandeilo area, the present study is the first to present a modern taxonomic review of these late Darriwilian-early Sandbian faunas that include approximately 20 multielement species. Most prominent are representatives of Amorphognathus, Baltoniodus, Eoplacognathus, and Plectodina. The study faunas have their own biogeographical character. The distinctive genera Complexodus, Protopanderodus, and Pygodus, which are common in coeval Baltoscandic faunas, are not present, but the occurrence of Amorphognathus, Baltoniodus, and Eoplacognathus provides a link to age equivalent Baltoscandic faunas. The presence of abundant specimens of Plectodina and less common representatives of Erismodus and Icriodella are reminiscent of North American Midcontinent faunas. This type of faunal assemblage is in some respects similar to those of the early Caradoc Series of the Welsh Borderland. Biostratigraphically diagnostic species indicate that the Llandeilo study succession ranges from the Eoplacognathus lindstroemi Subzone of the Pygodus serra Zone to the Baltoniodus variabilis Subzone of the Amorphognathus tvaerensis Zone.

2022 - Running across the Silurian/Devonian Boundary along Northern Gondwana: A Conodont Perspective [Articolo su rivista]
Ferretti, A.; Corriga, M. G.; Slavik, L.; Corradini, C.
abstract

The Global Stratotype Section and Point (GSSP) of the Silurian/Devonian boundary, Lower Devonian Series and Lochkovian Stage was formally placed in 1977 at Klonk, in the Czech Republic, at the first appearance of the graptolite Uncinatograptus uniformis uniformis (Přibyl). However, since then, correlation of this limit has been often hampered in carbonate facies where graptolites are uncommon or totally absent. A large calcareous deposition occurred at the Silurian/Devonian boundary along the northern and peri-Gondwana margin, thus representing an ideal location to select and test a possible additional biostratigraphic marker of the limit among conodonts. The first appearance of Caudicriodus hesperius almost simultaneously at the base of the Devonian in Bohemia, the Carnic Alps, Sardinia, Morocco and elsewhere indicates that this taxon is the conodont that best approximates the beginning of the Period. The first or last appearance of other species (e.g., Ozarkodina confluens, Zieglerodina klonkensis, Z. remscheidensis and Caudicriodus woschmidti) may help to recognise the boundary as well.

2022 - The significance of iron ooids from the middle Eocene of the Transylvanian Basin, Romania [Articolo su rivista]
Papazzoni, C. A.; Cavalazzi, B.; Brigatti, M. F.; Filipescu, S.; Foucher, F.; Medici, L.; Westall, F.; Ferretti, A.
abstract

The middle Eocene ironstone of the Transylvanian Basin, Romania, provides new insight into the genesis and paleoenvironmental significance of ferruginous ooids. An horizon at the base of the Ca ̆pus" Formation in north-western Romania, well known for the spectacular nummulite banks there exposed, documents a peculiar association of large foraminifera within a matrix dominated by millimetric Fe-ooids. These red- brownish Fe-ooids are well evident through the whitish colour of the carbonatic host matrix. An inte- grated analysis of the ooids, carried out by Environmental Scanning Electron Microscopy, Micro-X-ray Diffraction and Raman spectroscopy, allowed its detailed chemical and mineralogical characterization. Ooids are mostly composed of continuous concentric cortical layers of goethite interlayered by a few thin layers of phosphatic phases, whereas nuclei are made of ferruginous grains. No evidence of biological activity was detected in the cortex of the ooids to support a bio-mediated genesis. The occurrence of this ironstone testifies the existence of ferruginous bottom waters in the Eocene tropical/sub-tropical shallow-marine settings of the central Neotethyan Realm. The limited extension of the iron source area suggests that also local (e.g., not global) events could have been able to trigger iron ooidal deposition throughout the Phanerozoic.

2021 - Dead, fossil or alive: Bioapatite diagenesis and fossilization [Articolo su rivista]
Ferretti, A.; Medici, L.; Savioli, M.; Mascia, M. T.; Malferrari, D.
abstract

Calcium carbonate, silica and calcium phosphate have been selectively used by organisms in the production of mineralized hard parts throughout the Phanerozoic. Among these materials, bioapatite has enabled fundamental acquisitions in the evolution of life. Despite the remarkable biological success, the crystallography of bioapatite and the eventual modification of its lattice parameters over geological time have in contrast been scarcely investigated. In our study, we analyzed living, dead and fossil remains of both vertebrate and invertebrate organisms that biomineralized apatite, ranging from the Cambrian to the Recent, a time interval spanning over 500 million years. We detected in this way the bioapatite crystal features of the major phosphatic phyla (Brachiopoda, Arthropoda, Bryozoa, and Chordata: the latter including conodonts, cartilaginous and bony fishes, amphibians, reptiles, birds and mammals). Groups were investigated using either fossil or recent material (dead and/or alive, the former indicating organisms who died in recent times, the latter referring to material extracted from living organisms). The experimental results revealed that phosphatic materials from living, dead, and fossilized organisms have a distinct crystallographic signature. In fact, bioapatite in fossils is characterized by lower values of the crystal lattice cell parameter a (9.320–9.439 Å compared to 9.355–9.466 Å in dead and alive organisms), whereas the cell parameter c is less variable (6.857–6.911 Å for fossils and 6.861–6.902 Å for recent bioapatite); Student t-tests, applied to the means of these ranges of values (a¯=9.369 Å, c¯=6.887 Å, volume¯=523.6 Å3 for fossil values, a¯=9.415 Å, c¯=6.878 Å, volume¯=528.0 Å3 for recent values), highlighted significant differences between fossils and recent samples at a level p < 0.01 for the three cell parameters. These changes, which begin at the death of the organism and only stabilize in the ultimate stages of fossilization, mirror the isomorphic chemical substitutions within the crystal lattice and drive to a general decrease of the cell volume (i.e., the volume of the bioapatite hexagonal crystalline cell frame) over time, with an average reduction of 4.4 Å3 (0.8%) from alive to fossil organisms.

2021 - Rolling ironstones from earth and mars: Terrestrial hydrothermal ooids as a potential analogue of martian spherules [Articolo su rivista]
Di Bella, M.; Pirajno, F.; Sabatino, G.; Quartieri, S.; Barbieri, R.; Cavalazzi, B.; Ferretti, A.; Danovaro, R.; Romeo, T.; Andaloro, F.; Esposito, V.; Scotti, G.; Tripodo, A.; Italiano, F.
abstract

High-resolution images of Mars from National Aeronautics and Space Administration (NASA) rovers revealed mm-size loose haematite spherulitic deposits (nicknamed “blueberries”) similar to terrestrial iron-ooids, for which both abiotic and biotic genetic hypotheses have been proposed. Understanding the formation mechanism of these haematite spherules can thus improve our knowledge on the possible geologic evolution and links to life development on Mars. Here, we show that shape, size, fabric and mineralogical composition of the Martian spherules share similar-ities with corresponding iron spherules currently forming on the Earth over an active submarine hydrothermal system located off Panarea Island (Aeolian Islands, Mediterranean Sea). Hydrothermal fluids associated with volcanic activity enable these terrestrial spheroidal grains to form and grow. The recent exceptional discovery of a still working iron-ooid source on the Earth provides indications that past hydrothermal activity on the Red Planet is a possible scenario to be considered as the cause of formation of these enigmatic iron grains.

2021 - Uppermost Ordovician to lowermost Devonian conodonts from the Valentintörl section and comments on the post Hirnantian hiatus in the Carnic Alps [Articolo su rivista]
Corriga, Maria Giovanna; Corradini, Carlo; Pondrelli, Monica; Schönlaub, Hans-Peter; Nozzi, Lorenzo; Todesco, Rossana; Ferretti, Annalisa
abstract

A detailed biostratigraphic investigation has been carried out by means of conodonts in the uppermost Ordovician-lowermost Devonian sector of the Valentintörl cliff, located in the Austrian part of the Carnic Alps. Biostratigraphic data document in continuity all conodont biozones from the lowermost Ludlow to the upper Přídolí, with such a limited thickness to suggest that the Valentintörl section exposes the most condensed upper Silurian section in the Carnic Alps documented so far. A general discussion on the extension of the hiatus between Ordovician and Silurian sequences in the Carnic Alps is presented. Three new conodont species belonging to genera Cuspigrandiosa, Wurmiella and Zieglerodina are described, but left in open nomenclature awaiting more specimens to be collected.

2021 - Zooming in REE and Other Trace Elements on Conodonts: Does Taxonomy Guide Diagenesis? [Articolo su rivista]
Medici, Luca; Savioli, Martina; Ferretti, Annalisa; Malferrari, Daniele
abstract

Conodont elements are calcium phosphate (apatite structure) mineralized remains of the cephalic feeding apparatus of an extinct marine organism. Due to the high affinity of apatite for rare earth elements (REE) and other high field strength elements (HFSE), conodont elements were frequently assumed to be a reliable archive of sea-water composition and changes that had occurred during diagenesis. Likewise, the crystallinity index of bioapatite, i.e., the rate of crystallinity of biologically mediated apatite, should be generally linearly dependent on diagenetic alteration as the greater (and longer) the pressure and temperature to which a crystal is exposed, the greater the resulting crystallinity. In this study, we detected the uptake of HFSE in conodont elements recovered from a single stratigraphic horizon in the Upper Ordovician of Normandy (France). Assuming therefore that all the specimens have undergone an identical diagenetic history, we have assessed whether conodont taxonomy (and morphology) impacts HFSE uptake and crystallinity index. We found that all conodont elements are characterized by a clear diagenetic signature, with minor but significant differences among taxa. These distinctions are evidenced also by the crystallinity index values which show positive correlations with some elements and, accordingly, with diagenesis; however, correlations with the crystallinity index strongly depend on the method adopted for its calculation.

2021 - ʻConodont pearlsʼ do not belong to conodonts [Articolo su rivista]
Ferretti, A.; Malferrari, D.; Savioli, M.; Siepe, T.; Medici, L.
abstract

We investigated the mineralogical and chemical signatures of enigmatic microspherules commonly recovered in conodont residues and referred to in literature as ‘conodont pearls.’ Comparison between these ‘pearls,’ associated conodonts and other phosphatic skeletal elements present in the same stratigraphical level was run in an effort to reveal any possible relation between ‘conodont pearls’ and the joined groups so to finally provide a response on the affinity of these spherules.

2020 - Ethology of the trace fossil Chondrites: Form, function and environment [Articolo su rivista]
Baucon, A.; Bednarz, M.; Dufour, S.; Felletti, F.; Malgesini, G.; Neto de Carvalho, C.; Niklas, K. J.; Wehrmann, A.; Batstone, R.; Bernardini, F.; Briguglio, A.; Cabella, R.; Cavalazzi, B.; Ferretti, A.; Zanzerl, H.; McIlroy, D.
abstract

The behaviour of the iconic ichnogenus Chondrites is re-evaluated based on review of existing literature and analysis of novel data (macroscopic, thin section and ESEM-EDX observations; CT-scans and resin peels of modern analogues; computer-controlled serial grinding; morphometric analysis and theoretical morphology). The bedding plane expression of Chondrites is well-constrained by morphometry: (1) the angle of dichotomy formed by a pair of adjacent branches is typically between 30° and 56° (interquartile range; mean: 47°); (2) branching order is between 1 and 9; (3) branches are, on average, nine times longer than wide. In the third dimension, downward branching is dominant but bundled shafts and upward branching may be present. The size of Chondrites increased markedly from the Late Jurassic to the Late Cretaceous, suggesting that the tracemakers became larger and larger. Microfabric analysis of Chondrites shows active fill or, alternatively, passive fill of empty tunnels by currents or clay percolation, a new mechanism proposed herein. The tracemakers built Chondrites to obtain food: (1) vermiform deposit feeders produced Chondrites for searching for food in the sediment (fodinichnion); (2) asymbiotic bivalves built Chondrites for cultivating and directly ingesting bacteria (agrichnion); (3) chemosymbiotic bivalves produced Chondrites to provide symbionts with chemical agents. Chondrites was modified through the life of the tracemaker or it represented a part of the producer's lifespan. Chondrites — and its modern tracemaker(s) — is associated with a range of marine settings, including well-oxygenated, dysoxic and space-limited (nucleocave) environments. As such, Chondrites is regarded as an extremotolerant ichnotaxon.

2020 - GECkO: Global Events impacting COnodont evolution [Articolo su rivista]
Ferretti, Annalisa; Bancroft, Alyssa M.; Repetski, John E.
abstract

With a record that spans approximately 300 million years (late Cambrian through the Triassic/Jurassic transition, i.e., the “Conodontozoic”), conodonts witnessed all principal events in the evolution of life on Earth, from the invasion of the land to the exploration of the air, from the explosion of biomineralization in the oceans to the rise of dinosaurs and mammals, including three of the major extinction events that occurred in the Phanerozoic. Mainly used for biostratigraphic or geochemical studies, the potential of conodonts to help unravel changes perceived to be of global extent rarely has been explored. While specialists have identified rapid changes in conodont element morphology throughout their history, the conodont animal has often been perceived to have been a static entity in a constantly evolving world, when biological equilibrium in the oceans was undergoing profound alteration and faunal recoveries took place in phases that seem to have had recurrent patterns. It is now essential that we begin to further investigate how conodonts, as biologic entities, responded to or were impacted by paleogeographic changes, eustatic and climatic fluctuations, shifting redox conditions, and major faunal turnovers and reorganizations that took place during the “Conodontozoic”.

2020 - Leonardo da Vinci (1452-1519) and the birth of stratigraphy [Articolo su rivista]
Ferretti, A.; Vezzani, F.; Balini, M.
abstract

Most geological handbooks attribute the birth of stratigraphy to William Smith in the 19th century, after a brief mention of the pioneering contribution of Niels Stensen (Nicholaus Stenonis) who, almost a century before, had introduced in his Dissertationis prodromus of 1669 the principles of geometric relationships between strata. On the contrary, Leonardo da Vinci is related, among other scientists, to the intuition that fossils are remains of living organisms. Da Vinci was indeed much more than that. All concepts commonly associated with stratigraphy, e. g., fossils as age-diagnostic tools, geometric properties and position of strata, correlations of stratigraphic successions, are deeply-rooted in Leonardo’s writings and fully expressed in his paintings, integrated in mature observations and reproduction of the landscape. The celebration of the five-hundredth anniversary of Leonardo’s death gives us the opportunity to finally link Leonardo da Vinci to the birth of modern stratigraphy.

2020 - Mineralogy and crystallization patterns in conodont bioapatite from first occurrence (Cambrian) to extinction (end-Triassic) [Articolo su rivista]
Medici, Luca; Malferrari, Daniele; Savioli, Martina; Ferretti, Annalisa
abstract

Bioapatite represents an important acquisition in the evolution of life, both in the seas and on land. Vertebrates applied calcium-phosphate biominerals to grow their skeletal support and to shape their teeth, while some invertebrates sheltered their soft parts within apatite shells. Conodonts were the first among vertebrates to experiment with skeletal biomineralization of tooth-like elements in their feeding apparatus. Spanning a time record of over 300 million years, they offer a unique tool to test possible variation in bioapatite structure from the experimentation of a very primitive biomineralization type to a more evolute pattern just before going extinct. X-ray microdiffraction carried out through an X-ray micro-diffractometer, integrated with environmental scanning electron microscopy coupled with chemical microanalyses (ESEM-EDX), has been applied in this study to investigate conodont element crystal structure throughout the entire stratigraphic range of these organisms. In particular, bioapatite crystallographic cell parameters have been calculated for about one hundred conodont elements ranging from the late Cambrian to the Late Triassic. Resulting data clearly indicate two distinct distribution plots of cell parameters for paraconodonts and euconodonts. In contrast, age, taxonomy, geographic provenance and CAI do not affect the dimension of the bioapatite crystal cells. Conodont bioapatite crystallographic cell parameters have been compared with cell parameters resulting from phosphatic/phosphatized material (ostracodes, brachiopods, bryozoans, and fish teeth) present in the same residues producing conodonts. Resulting values of the cell parameters are, in general, mainly correlated with the type of organisms even if, for some of them, a correlation also with age cannot be completely ruled out. According to our data, primary bioapatite appears to imprint a key signature on fossil crystal-chemistry (crystal structure and major chemical element contents), while the contribution of fossilization and diagenetic processes seems less relevant.

2019 - Armoured sponge spicules from Panarea Island (Italy): Implications for their fossil preservation [Articolo su rivista]
Ferretti, A.; Messori, F.; Di Bella, M.; Sabatino, G.; Quartieri, S.; Cavalazzi, B.; Italiano, F.; Barbieri, R.
abstract

A variety of calcareous and siliceous skeletal components are associated with exceptional, still active deposits of modern iron ooids off Panarea, one of the volcanic islands of the Aeolian Arc (Tyrrhenian Sea, Italy). Both ooids and skeletal components occur as loose sediments influenced by submarine hydrothermal fluid vents. Whereas iron ooids are exclusively made of goethite laminae primarily nucleated on volcaniclastic material, sponge spicules – that represent most of the siliceous skeletal component – develop laminated coatings (concretions) of varying sizes. This partial or total coating consists of regularly banded Fe‒rich layers exhibiting the same textural features and mineralogical composition (goethite) of the ooid cortex developed around inorganic cores. Spicules did not reveal any obvious attaching structure or interfingering with the surrounding coating and did not undergo bioerosion or any other evidence of biological intervention during their development. A hydrothermal origin, compatible with the general setting, is therefore proposed for these armoured sponge spicules. We believe that this unique modern case of iron concretions produced on siliceous spicules can contribute to explain other known fossil cases as well as to understand the taphonomy of this type of biogenic silica that seems rarely to have been preserved in such an extreme habitat.

2019 - How Much Can We Trust Major Element Quantification in Bioapatite Investigation? [Articolo su rivista]
Malferrari, D.; Ferretti, A.; Mascia, M. T.; Savioli, M.; Medici, L.
abstract

Bioapatite is probably the key factor in the unreplicated success of vertebrates. Chemical data on bioapatite composition can be achieved on a solid sample by using different analytical tools such as spectroscopic and spectrometric methods. As analytical outputs can be affected by the physical-chemical characteristics of the sample matrix, an internal standard is usually required to correct and validate the results. Bioapatite lattice can accommodate iso- and heterovalent substitutions during life or diagenesis varying its chemical composition through (geological) time. If on the one hand, this makes bioapatite a unique archive of physical and chemical information for both the living cycle and the events occurring after death, on the other, it excludes the identification of a sole internal standard. Here, we propose a method to measure major element concentration with specific care for P, Ca, Mg, Na, K, Si, Al, and Fe, which are the main substituent atoms in bioapatite, through homemade matrix-matched external calibration standards for laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS). We tested the method on living and fossil shark teeth, critically comparing the results obtained using other analytical techniques and certified external standards. We demonstrated that matrix-matched calibration in LA-ICPMS is mandatory for obtaining a reliable chemical characterization even if factors such as matrix aggregation variability, diverse presence of volatile compounds, the fossilization footprint, and the instrumental variability can represent further variability parameters.

2019 - Lochkovian (Lower Devonian) marine-deposits from the Rio Malinfier West section (Carnic Alps, Italy) [Articolo su rivista]
Corradini, Carlo; Corriga, Maria G.; Pondrelli, Monica; Serventi, Paolo; Simonetto, Luca; Ferretti, Annalisa
abstract

The Rio Malinfier West section in the central Carnic Alps provides important data on the evolution of the Lochkovian (Lower Devonian) sedimentary basins of the Variscan belt. An exposure of about 100 m documents five lithostratigraphic units (Alticola, Rauchkofel, Nölbling, La Valute and Findenig formations) spanning in age from the latest Silurian to the Early Devonian. The complex structural setting of the section results from a main fault dividing the succession in two separate segments. A precise lithological characterization was carried on at a macro- and micro-scale. Macrofauna includes, among others, abundant cephalopods and crinoids (loboliths). The biostratigraphic assignment to the uppermost Silurian-lowermost Devonian (Lochkovian) was possible basing on a moderately abundant conodont fauna, that provided thirty-two taxa belonging to thirteen genera, among which the new species Zieglerodina schoenlaubi. The Rio Malinfier West section testifies that a differentiation between shallow and deep water parts of the Devonian basin was already present during Lochkovian times, prior to the establishment of the conditions enabling the colonization of the well-known upper Lower-Middle Devonian reef buildings.

2019 - Modern Iron Ooids of Hydrothermal Origin as a Proxy for Ancient Deposits [Articolo su rivista]
Di Bella, M.; Sabatino, G.; Quartieri, S.; Ferretti, A.; Cavalazzi, B.; Barbieri, R.; Foucher, F.; Messori, F.; Italiano, F.
abstract

We constrained the origin and genetic environment of modern iron ooids (sand-sized grains with a core and external cortex of concentric laminae) providing new tools for the interpretation of their fossil counterparts as well as the analogous particles discovered on Mars. Here, we report an exceptional, unique finding of a still active deposit of submillimetric iron ooids, under formation at the seabed at a depth of 80 m over an area characterized by intense hydrothermal activity off Panarea, a volcanic island north of Sicily (Italy). An integrated analysis, carried out by X-ray Powder Diffraction, Environmental Scanning Electron Microscopy, X-ray Fluorescence and Raman spectroscopy reveals that Panarea ooids are deposited at the seafloor as concentric laminae of primary goethite around existing nuclei. The process is rapid, and driven by hydrothermal fluids as iron source. A sub-spherical, laminated structure resulted from constant agitation and by degassing of CO2-dominated fluids through seafloor sediments. Our investigations point the hydrothermal processes as responsible for the generation of the Panarea ooids, which are neither diagenetic nor reworked. The presence of ooids at the seawater-sediments interface, in fact, highlights how their development and growth is still ongoing. The proposed results show a new process responsible for ooids formation and gain a new insight into the genesis of iron ooids deposits that are distributed at global scale in both modern and past sediments.

2018 - Deciphering the geology of some Darriwilian–Sandbian (Ordovician) ‘ghost’ formations in the UK and North America using olistoliths in marine debris flows [Articolo su rivista]
Bergström, Stig M.; Ferretti, Annalisa
abstract

Olistostromes with calcareous olistoliths are rare components in the Ordovician successions inNWEurope and North America, having been described from only a small number of localities. One of the best exposed, but least known, is in the Garn Formation in coastal outcrops in Anglesey in northwestern Wales. Here, in the graptolite-bearing shales of the Garn Formation, there are numerous limestone olistoliths that are derived from an otherwise unknown ‘ghost’ formation whose original depositional site remains an enigma. These olistoliths contain a Baltoscandian type of conodont fauna that is otherwise unknown in Wales and England. It represents the Baltoniodus variabilis Subzone of the Amorphognathus tvaerensis Zone. Similar, but slightly older, conodont faunas are recorded from olistoliths in the Tweeddale Member of the Shinnel Formation in southern Scotland and in probable olistoliths of the Cobbs Arm Limestone in northeasternmost Newfoundland. Approximately coeval conodont faunas are present in calcareous olistoliths in the Woods Hollow Shale of West Texas and the Womble Shale in the Ouachita Mountains of Arkansas, USA. Lithological and conodont evidence indicates that the calcareous olistoliths were derived from carbonate sediments deposited in relatively shallow water. It is concluded that the study of ‘ghost’ formation olistoliths may provide otherwise unavailable but important data bearing on the marine depositional history of a particular region.

2018 - HOW DID VERTEBRATES SHARPEN THEIR TEETH? A NEW PERSPECTIVE IN BIOAPATITE ANALYSIS [Capitolo/Saggio]
Savioli, Martina; Ferretti, Annalisa; Medici, Luca; Malferrari, Daniele
abstract

HOW DID VERTEBRATES SHARPEN THEIR TEETH? A NEW PERSPECTIVE IN BIOAPATITE ANALYSIS

2017 - Chrono-, litho- and conodont bio-stratigraphy of the Rauchkofel Boden Section (Upper Ordovician–Lower Devonian), Carnic Alps, Austria [Articolo su rivista]
Schönlaub, Hans Peter;  Corradini, Carlo;   Corriga, Maria G.; Ferretti, Annalisa
abstract

An updated stratigraphy of the Rauchkofel Boden Section, a classical reference section for the Carnic Alps that exposes rocks from the Katian (Upper Ordovician) to the Pragian (Lower Devonian) is here presented, following latest developments in conodont taxonomy and biostratigraphy, as well as in chrono - stratigraphy, and the recent introduction of a new lithostratigraphic outline of the Carnic Alps. The original conodont collection of the ’70s and ʼ80s was restudied and complemented by a detailed resampling in order to achieve a more precise conodont biostratigraphic assignment. Twenty-five conodont Zones are now documented. The lithostratigraphy is precisely fixed to the new lithostratigraphic scheme of the Pre-Variscan sequence by definition of seven distinct formations. Finally, the position of chronostratigraphic boundaries is discussed.

2017 - Conodonts in Ordovician biostratigraphy [Articolo su rivista]
Bergström, Stig M.; Ferretti, Annalisa
abstract

The long time interval after Pander's (1856) original conodont study can in terms of Ordovician conodont biostratigraphical research be subdivided into three periods, namely the Pioneer Period (1856-1955), the Transition Period (1955-1971) and the Modern Period (1971-Recent). During the pre-1920s, the few published conodont investigations were restricted to Europe and North America and were not concerned about the potential use of conodonts as guide fossils. Although primarily of taxonomic nature, the pioneer studies by Branson & Mehl, Stauffer and Furnish during the 1930s represent the beginning of the use of conodonts in Ordovician biostratigraphy. However, no formal zones were introduced until Lindström (1955) proposed four conodont zones in the Lower Ordovician of Sweden, which marks the end of the Pioneer Period. Because Lindström's zone classification was not followed by similar work outside Baltoscandia, the time interval up to the late 1960s can be regarded as a Transition Period. A milestone symposium volume, entitled 'Symposium on Conodont Biostratigraphy' and published in 1971, summarized much new information on Ordovician conodont biostratigraphy and is taken as the beginning of the Modern Period of Ordovician conodont biostratigraphy. In this volume, the Baltoscandic Ordovician was subdivided into named conodont zones, whereas the North American Ordovician succession was classified into a series of lettered or numbered faunas. Although most of the latter did not receive zone names until 1984, this classification has been used widely in North America. The Middle and Upper Ordovician Baltoscandic zone classification, which was largely based on evolutionary species changes in lineages and hence includes phylozones, has subsequently undergone only minor changes and has been used slightly modified also in some other regions, such as New Zealand, China and eastern North America. The great importance of conodonts in Ordovician biostratigraphy is shown by the fact that conodonts are used for the definition of two of the seven global stages, and seven of the 20 stage slices, now recognized within this system.

2017 - Diagenesis does not invent anything new: Precise replication of conodont structures by secondary apatite [Articolo su rivista]
Ferretti, Annalisa; Malferrari, Daniele; Medici, Luca; Savioli, Martina
abstract

Conodont elements are important archives of sea/pore water chemistry yet they often exhibit evidence of diagenetic mineral overgrowth which may be biasing measurents. We decided to investigate this phenomenon by characterising chemically and crystallographically, the original biomineral tissue and the diagenetic mineral nature of conodont elements from the Ordovician of Normandy. Diagenetic apatite crystals observed on the surface of conodont elements show distinctive large columnar, blocky or web-like microtextures. We demonstrate that these apatite neo-crystals exhibit the same chemical composition as the original fossil structure. X-ray microdiffraction has been applied herein for the first time to conodont structural investigation. Analyses of the entire conodont element surface of a variety of species have revealed the existence of a clear pattern of crystal preferred orientation. No significant difference in unit cell parameters was documented between the newly formed apatite crystals and those of the smooth conodont surfaces, thus it emerges from our research that diagenesis has strictly replicated the unit cell signature of the older crystals.

2017 - Exceptionally preserved conodont apparatuses with giant elements from the Middle Ordovician Winneshiek Konservat-Lagerstätte, Iowa, USA [Articolo su rivista]
Liu, Huaibao P.; Bergström, Stig M.; Witzke, Brian J.; Briggs, Derek E. G.; Mckay, Robert M.; Ferretti, Annalisa
abstract

Considerable numbers of exceptionally preserved conodont apparatuses with hyaline elements are present in the middle-upper Darriwilian (Middle Ordovician, Whiterockian) Winneshiek Konservat-Lagerstätte in northeastern Iowa. These fossils, which are associated with a restricted biota including other conodonts, occur in fine-grained clastic sediments deposited in a meteorite impact crater. Among these conodont apparatuses, the common ones are identified as Archeognathus primus Cullison, 1938 and Iowagnathus grandis new genus new species. The 6-element apparatus of A. primus comprises two pairs of archeognathiform (P) and one pair of coleodiform (S) elements. The 15-element apparatus of I. grandis n. gen. n. sp. is somewhat reminiscent of the prioniodinid type and contains ramiform elements of alate (one element) and digyrate, bipennate, or tertiopedate types (7 pairs). Both conodont taxa are characterized by giant elements and the preservation of both crowns and basal bodies, the latter not previously reported in Ordovician conodont apparatuses. Comparison of the apparatus size in the Winneshiek specimens with that of the Scottish Carboniferous soft-part-preserved conodont animals suggests that the Iowa animals were significantly larger than the latter. The apparatus of A. primus differs conspicuously from the apparatuses of the prioniodontid Promissum from the Upper Ordovician Soom Shale of South Africa although the apparatus architecture of I. grandis n. gen. n. sp. shows some similarity to it. Based on the Winneshiek collections, a new family Iowagnathidae in Conodonta is proposed.

2017 - From the editors [Articolo su rivista]
Ferretti, A.; Balini, M.
abstract

2017 - Lochkovian conodonts in the Rio Malinfier West section [Articolo su rivista]
CORRIGA MARIA, Giovanna; Corradini, Carlo; Ferretti, Annalisa; Pondrelli, Monica; Simonetto, Luca; Serventi, Paolo
abstract

The Lockhovian conodont fauna from the new Rio Malinfier section is discussed and commented.

2017 - Middle-Upper Ordovician conodonts from the Ffairfach and Golden Grove groups in South Wales, United Kingdom [Capitolo/Saggio]
Ferretti, A.; Bergström, S. M.
abstract

The conodont fauna of the reference succession of the British regional Llandeilian Stage of the Llanvirn Series was fi rst described in a now classical study by Rhodes (1953) using single element (form) taxonomy. Although some subsequent authors have recorded a few additional conodont taxa from this late Darriwilian- Sandbian interval at Llandeilo and coeval strata in nearby areas (e.g. Bergström, 1964, 1971; Bergström and Orchard, 1985), the present study is the fi rst to present a complete taxonomic review of these faunas, which include approximately 20 multielement species. Most prominent among the compound conodont taxa in these fauna from South Wales are representatives of Amorphognathus, Baltoniodus, Eoplacognathus, Icriodella, and Plectodina. Biostratigraphically diagnostic species indicate that the Llandeilo study succession ranges from the Eoplacognathus lindstroemi Subzone of the Pygodus serra Zone to the Baltoniodus variabilis Subzone of the Amorphognathus tvaerensis Zone. The Llandeilo faunas have their own biogeographic character. The common occurrence of species of Plectodina and less common representatives of Erismodus and Icriodella are reminiscent of coeval North American Midcontinent faunas but the latter lack Baltoniodus and Eoplacognathus. The Llandeilo conodont species association is also somewhat similar to that of the Caradoc Series of Welsh Borderland (Bergström, 1971; Savage and Bassett, 1985) but the latter differs in lacking, among others, Baltoniodus, and Eoplacognathus. These two genera are common in coeval Baltoscandic faunas, but the latter also contain such characteristic genera as Complexodus, Protopanderodus, and Pygodus, which are not represented in our Llandeilo collections. Because specimens of Plectodina are quite rare, and Erismodus is missing, in the coeval Baltoscandic faunas, the faunal similarity between the Baltoscandic and the South Wales faunas is quite limited.

2017 - Mineralogical characterization of apatite biominerals: preliminary results [Capitolo/Saggio]
Medici, Luca; Ferretti, Annalisa; Malferrari, Daniele; Cavalazzi, Barbara; Savioli, Martina
abstract

Bioapatite fossils are investigated and compared by the use of microdiffraction technique.

2017 - New types of exceptionally large conodont apparatuses with hyaline elements from the Middle Ordovician Winneshiek Konservat-Lagerstätten in Iowa, USA [Capitolo/Saggio]
Liu, H.; Bergström, S. M.; Ferretti, A.; Briggs, D. E. G.; Witzke, B. J.; Mckay, R. M.
abstract

An exceptional conodont fossil-lagerstatte is described.

2017 - Organism-substrate interactions and astrobiology: Potential, models and methods [Articolo su rivista]
Baucon, Andrea; de Carvalho, Carlos Neto; Barbieri, Roberto; Bernardini, Federico; Cavalazzi, Barbara; Celani, Antonio; Felletti, Fabrizio; Ferretti, Annalisa; Schönlaub, Hans Peter; Todaro, Mary Antonio Donatello; Tuniz, Claudio
abstract

Organism-substrate interactions and their products – biogenic structures – are important biosignatures on Earth. This study discusses the application of ichnology – the study of organism-substrate interactions – to the search for present and past life beyond Earth. Three main questions are addressed: (1) Why to look for biogenic structures (i.e. traces and ichnofabrics) beyond Earth? (2) What biogenic structures to expect on other planets, moons and asteroids? (3) How to study extraterrestrial biogenic structures? Review of terrestrial evidence highlights a set of properties that make traces and ichnofabrics important for the search of potential extraterrestrial life: trace fossils preserve the activity of soft-bodied organisms; biogenic structures are resilient to processes that obliterate other biosignatures (i.e. mechanical and chemical degradation, diagenesis, tectonism and metamorphism); traces are very visible biosignatures; traces indicate environment and behaviour; traces can be universal biosignatures, i.e., biosignatures ideally suited for detecting any type of life. A model of organism-substrate interactions beyond Earth is here proposed. Expected extraterrestrial traces are those that manifest behaviours that allow to maintain homeostasis: excavations, meandering traces and biodeposition structures. Most of the existing rovers and orbiters provide basic instruments for searching these traces. It is here suggested that the search for extraterrestrial biogenic structures by rovers would also benefit from artificial adjustable lighting, GPR, LiDAR, and drilling equipment with optical televiewer. In this study, open-access databases of rover and orbiter imagery have been searched for traces and ichnofabrics, but no unquestionable evidence of biogenic structures beyond Earth has been found besides those produced by humans. This sounds along the lines of the famous Fermi Paradox: if the universe is teeming with aliens, where are their traces? Results of this search show that habitable environments are not the only place to look for biogenic structures; non-habitable environments such as moons without atmosphere can favour the preservation of shallow-tier traces. The better preservation potential of traces compared to other biosignatures greatly widens the issue of planetary protection, including the interaction between astronauts or vehicles and the substrate may produce disturbances. Although this study highlights a new direction of study with the tools and concepts of ichnology, dialogue between the astrobiological and ichnological communities is needed to use its full potential and possibly answer one of the major questions of science: Does life exist beyond Earth?

2017 - Special Issue: The Contribution of Fossils to Chronostratigraphy, 150 Years after Albert Oppel [Curatela]
Balini, Marco; Ferretti, Annalisa; Finney, Stan; Monechi, Simonetta
abstract

The 2nd International Symposium on Stratigraphy, STRATI 2015, held in Graz, Austria in July 2015 provided the opportunity to celebrate the 150th anniversary of the death of one of the most prominent scientists in the history of geology, Albert Oppel (1831–65), a specialist on Jurassic ammonoids who is widely considered as the father of modern bio- and chronostratigraphy. Surprisingly, despite the rich and varied programme of international symposia and workshops running at that time and devoted to different aspects of palaeontology and sedimentary geology, this important anniversary went apparently unnoticed and no special events were scheduled. At the end of 2014, we decided therefore to submit to the Organizing Committee of STRATI 2015 a proposal for a special session devoted to Oppel and to a discussion of the importance of fossils for dating and correlating of sedimentary rocks. The session was accepted and the publication of selected papers resulting from it was welcomed and encouraged by the editors of Lethaia. The invited contributions were deliberately wide-ranging in order to bring together apparently unrelated lines to assess the significance of diverse fossil groups through a long time span and to explore their potential for high-resolution stratigraphy and their modern contribution to chronostratigraphy. Our invitation was accepted by many specialists working on different fossil groups, representing the entire Phanerozoic stratigraphical record. The Oppel session was the most successful of the Graz Symposium both in terms of contributions and public attendance. It attracted 25 participants from14 countries of all continents. Several speakers accepted our further invitation to contribute to this Thematic Issue. In the following sections, we briefly offer a starting point focusing on the extraordinary profile of Albert Oppel and present later the general framework of the Oppel Thematic Issue.

2017 - The Cellon section [Articolo su rivista]
Corradini, Carlo; CORRIGA MARIA, Giovanna; Ferretti, Annalisa; SCHÖNLAUB HANS, Peter
abstract

The Cellon section, a reference section for Silurian and Devonian specialists, is described and recent data discussed.

2017 - The contribution of fossils to chronostratigraphy, 150 years after Albert Oppel [Articolo su rivista]
Balini, Marco; Ferretti, Annalisa; Finney, Stanley; Monechi, Simonetta
abstract

The 150th anniversary of the death of Albert Oppel (1831–65) provided the opportunity to celebrate this outstanding stratigrapher with a Thematic Issue dedicated to the importance of fossils for dating and correlating of sedimentary rocks. In this issue, we analyse Oppel’s significant contribution to modern chronostratigraphy, before exploring the Phanerozoic through all its major fossil groups, to verify if fossils are still able to make a significant contribution to chronostratigraphy. The extraordinary merit of Oppel’s work has been the demonstration that fossils can be used to sub-divide sedimentary sequences into zones, which in turn might be organized in higher chronostratigraphical units. The zone for Oppel is characterized by the distinctive fossil content, and his view strongly influenced the development of the standard chronostratigraphical scale for about one century, until the introduction, in the 1950s, of the log-based range chart as the common practice to study the fossil record of sedimentary successions. This approach forced the stratigraphers to shift the focus from the fossil content of the zones to their boundaries. This new view allowed for the introduction of new kind of zones with precisely defined boundaries based on bioevents and to the decline of the Oppel Zone. This turning point in the history of chronostratigraphy was fuelled by the International Commission on Stratigraphy programme of definition of the units of the International Chronostratigraphic Chart based on the boundary stratotype and point (GSSP) concept, which started in 1973.

2017 - The evolution of conodont form through time [Capitolo/Saggio]
Ferretti, A.; Bancroft, A.; Bergström, S.; Donoghue, P. C. J.; Goudemand, N.; Macleod, N.; Purnell, ; M. A., & REPETSKI; J., E.
abstract

Conodont shape and size is revised through the full stratigraphic record of the fossil group.

2017 - Upper Ordovician conodonts in the Valbertad section [Articolo su rivista]
Bagnoli, Gabriella; Ferretti, Annalisa; Simonetto, Luca; Corradini, Carlo
abstract

The Late Ordovician conodont fauna from the Valbertad Section (Carnic Alps) is briefly revised according to the new Chronostratigraphic Chart.

2016 - Conodonts in the Ordovician biostratigraphy of the British Isles: an update [Abstract in Atti di Convegno]
Ferretti, Annalisa; Bergström, Stig M.
abstract

An update of the conodont biostratugraphy is provided for the Ordovician.

2016 - Crystals on the rocks. Apatite overgrowth on conodont elements from the Late Ordovician of Normandy, France [Abstract in Atti di Convegno]
Ferretti, Annalisa; Malferrari, Daniele; Medici, Luca; Savioli, Martina
abstract

Apatite overgrowth patterns on Ordovician conodonts are here referred to metamorphism.

2016 - Editorial [BOLLETTINO DELLA SOCIETÀ PALEONTOLOGICA ITALIANA, vol. 55(2), 2016] [Articolo su rivista]
Ferretti, Annalisa; Balini, Marco
abstract

Editorial to the Volume.

2016 - In a galaxy far, far away...traces? Astrobiological potential of Ichnology [Abstract in Atti di Convegno]
Baucon, Andrea; De Carvalho, Carlos Neto; Barbieri, Roberto; Bernardini, Federico; Cavalazzi, Barbara; Celani, Antonio; Felletti, Fabrizio; Ferretti, Annalisa; Schönlaub, Hans Peter; Todaro, Mary Antonio Donatello; Tuniz, Claudio
abstract

The paper explores the relation between organisms and sediments looking for possible indications for exploring traces of life far far away.

2016 - Overgrowth of apatite crystals on the surface of Late Ordovician conodonts from Normandy, northern France [Abstract in Atti di Convegno]
Ferretti, Annalisa; Malferrari, Daniele; Medici, Luca; Savioli, Martina
abstract

Peculiar apatite overgrowth on Ordovician conodont elements are described.

2016 - Silurian agglutinated foraminifera from the Dingle Peninsula, Ireland [Articolo su rivista]
Kaminski, Michael A.; Ferretti, Annalisa; Messori, Fabio; Papazzoni, Cesare Andrea; Sevastopulo, George
abstract

An assemblage of primitive agglutinated foraminifera is reported for the first time from Silurian limestones from the Dingle Peninsula, Ireland. The assemblage is dominated by tubothalamids (Rectoammodiscus and rare Sansabaina), with less abundant monothalamids (Psammosiphonella and Psammosphaera). At the species level, the agglutinated foraminiferal assemblage is identical to those described previously from the Silurian of North America but is of lower diversity. The foraminiferal assemblage has limited potential for stratigraphic correlation as long-ranging taxa are present. The co-occurring conodont fauna enables an assignment to the early Ludlow.

2016 - Silurian anoxic events at the Cellon section (Austria) through an ichnofabric eye [Abstract in Atti di Convegno]
Baucon, Andrea; Ferretti, Annalisa; Schönlaub, Hans Peter
abstract

Silurian ichnofabrics are preliminary described from the Silurian Cellon Section of the Austrian Carnic Alps.

2016 - Stars in the Silurian sky: Echinoderm holdfasts from the Carnic Alps [Articolo su rivista]
Ferretti, Annalisa; Ausich, William I.; Corradini, Carlo; Corriga, Maria Giovanna; Schönlaub, Hans Peter
abstract

A small collection of echinoderm holdfasts from the Ludlow Cardiola Formation of the Carnic Alps (Austria) contains a wide range of morphologies as a response of environmental adaptation. In general, the holdfasts have a globous and massive dome-like profile with several processes arranged in a sub-radial disposition, so to create a sort of ‘star-like’ outline. A small central depression is common but not present on all specimens. The distinctive holdfasts are preserved in an iron-rich phase, documenting a substitution that has also affected other non-echinoderm calcareous material.

2016 - Updated conodont biostratigraphy of the Rauchkofel Boden Section (Katian-Pragian), Carnic Alps, Austria [Abstract in Atti di Convegno]
Schönlaub, Hans Peter; Corradini, Carlo; Corriga, Maria Giovanna; Ferretti, Annalisa
abstract

Updated conodont stratigraphy in the Lower Palaeozoic of the Carnic Alps

2016 - Zinc incorporation in the miliolid foraminifer Pseudotriloculina rotunda under laboratory conditions [Articolo su rivista]
Nardelli, M. P.; Malferrari, Daniele; Ferretti, Annalisa; Bartolini, A.; Sabbatini, A.; Negri, A.
abstract

The incorporation rate of Zn into the calcareous tests of Pseudotriloculina rotunda was investigated in culture in order to evaluate the possibility of using Zn/Ca ratios as a pollution proxy. Foraminifera were incubated at zinc concentrations up to 10-fold higher than unpolluted seawater (sea + 10 mg Zn/L) during 70 days. New calcite was investigated under the Environmental Scanning Electron Microscope (ESEM), for potential alteration of test structure. Laser ablation-Inductively Coupled Plasma-Mass spectrometry (LA-ICP-MS) was used to quantify Zn contents. The analyses revealed that test structure is not visibly altered by the presence of zinc. However, significant Zn incorporation is detected by the LA-ICP-MS. The zinc partition coefficient, DZn, decreases at increasing Zn concentrations (from 4.03 ± 0.06 to 0.2 ± 0.01) and the zinc is incorporated into the calcite not necessarily linearly.

2015 - Alticola Formation [Articolo su rivista]
Ferretti, Annalisa; Schönlaub, Hans Peter; Corradini, Carlo; Corriga, Maria Giovanna; Pondrelli, Monica; Simonetto, Luca; Serventi, Paolo
abstract

2015 - Bioturbation beyond Earth: potential, methods and models of astroichnology [Abstract in Atti di Convegno]
Baucon, Andrea; de Carvalho, Carlos Neto; Bernardini, Federico; Cardini, Andrea Luigi; Cavalazzi, Barbara; Celani, Antonio; Felletti, Fabrizio; Ferretti, Annalisa; Schönlaub, Hans Peter; Todaro, Mary Antonio Donatello
abstract

Traces – burrows, borings, footprints – are important evidences of biological behaviour on Earth, yet they received relatively little attention in the field of astrobiology. This study aims to discuss the application of ichnology (i.e. the study of life activity traces) to the search for past and modern life beyond Earth (i.e. herein called Astroichnology).

2015 - Bischofalm Formation [Articolo su rivista]
Schönlaub, Hans Peter; Ferretti, Annalisa; Corradini, Carlo; Corriga, Maria Giovanna; Pondrelli, Monica; Simonetto, Luca
abstract

2015 - Can facies act as a chronostratigraphical tool? [Abstract in Atti di Convegno]
Ferretti, Annalisa; Cavalazzi, Barbara; Mclaughlin, Patrick I.; Barbieri, Roberto; Emsbo, Poul; Foucher, Frédéric; Malferrari, Daniele; Messori, Fabio; Westall, Frances
abstract

Results demonstrate that the Appalachian ironstones seem to reflect the same microbially-mediated iron mineralization already documented in the Carnic Alps.

2015 - Cardiola Formation [Articolo su rivista]
Ferretti, Annalisa; Schönlaub, Hans Peter; Corradini, Carlo; Corriga, Maria Giovanna; Pondrelli, Monica; Simonetto, Luca; Serventi, Paolo
abstract

2015 - Conodonts in Ordovician Chronostratigraphy [Abstract in Atti di Convegno]
Bergström, Stig M.; Ferretti, Annalisa
abstract

The great importance of conodonts in Ordovician chronostratigraphy is shown by the fact that conodonts are used for the definition of two of the seven global stages, and seven of the 18 stage slices, now recognized within this system.

2015 - Conodonts in the Upper Ordovician Keisley Limestone of northern England: taxonomy, biostratigraphical significance and biogeographical relationships [Articolo su rivista]
Bergström, Stig M.; Ferretti, Annalisa
abstract

The classical fauna from the Keisley Limestone, one of the first Upper Ordovician conodont faunas described from the UK, is re-evaluated based on relatively abundant collections of well-preserved conodont elements representing 20 multielement taxa. Common taxa are representatives of Amorphognathus duftonus, Birksfeldia circumplicata, Eocarniodus aff. E. gracilis, Hamarodus brevirameus, Scabbardella altipes, Strachanognathus parvus and several coniform species. These occur with more rare specimens of, among others, Aphelognathus nudus, Amorphognathus aff. A. ordovicicus, Dapsilodus mutatus, Icriodella prominens, Icriodella rhodesi sp. nov. and Protopanderodus liripipus. One new species is proposed, and the concepts of Birksfeldia, Gamachignathus, Icriodella and Notiodella are discussed. It is proposed that Birksfeldia is a senior synonym of Gamachignathus and Notiodella a junior synonym of Icriodella. The described Keisley species association, which represents the A. ordovicicus Zone and is of late Katian (Ka4) age, is closely similar to those of the Boda Limestone of south-central Sweden and some other European faunas, but coeval shallow-water faunas from eastern North America differ in several respects from these European faunas. Biostratigraphy and carbon isotope chemostratigraphy indicate that most of the Keisley Limestone is of late Katian age.

2015 - Editorial [BOLLETTINO DELLA SOCIETÀ PALEONTOLOGICA ITALIANA, Vo. 54, 2015] [Articolo su rivista]
Ferretti, Annalisa; Balini, Marco
abstract

Editorial to the Volume.

2015 - Kok Formation [Articolo su rivista]
Ferretti, Annalisa; Schönlaub, Hans Peter; Corradini, Carlo; Corriga, Maria Giovanna; Pondrelli, Monica; Simonetto, Luca; Serventi, Paolo
abstract

2015 - Nölbling Formation [Articolo su rivista]
Schönlaub, Hans Peter; Ferretti, Annalisa; Corradini, Carlo; Corriga, Maria Giovanna; Pondrelli, Monica; Simonetto, Luca
abstract

2015 - Plöcken Formation [Articolo su rivista]
Schönlaub, Hans Peter; Ferretti, Annalisa
abstract

2015 - Rauchkofel Formation [Articolo su rivista]
Corradini, Carlo; Corriga, Maria Giovanna; Pondrelli, Monica; Schönlaub, Hans Peter; Simonetto, Luca; Spalletta, Claudia; Ferretti, Annalisa
abstract

2015 - The Pre-Variscan sequence of the Carnic Alps (Austria and Italy): an introduction [Articolo su rivista]
Corradini, Carlo; Suttner, Thomas; Ferretti, Annalisa; Pohler, Susan; Pondrelli, Monica; Schönlaub, Hans Peter; Spalletta, Claudia; Venturini, Corrado
abstract

2015 - Trans-Atlantic application of the Baltic Middle and Upper Ordovician carbon isotope zonation [Articolo su rivista]
Bergström, Stig M.; Saltzman, Matthew R.; Leslie, Stephen A.; Ferretti, Annalisa; Young, Seth A.
abstract

Application of the recently introduced Baltic δ13C isotope zonation to a composite North American Darriwilian through Hirnantian succession shows that in most intervals there is good trans-Atlantic agreement not only between the isotope zones but also with the available biostratigraphic data. This indicates that this isotope zonation is a useful tool for improving previously uncertain long-distance correlations.

2015 - Uqua Formation [Articolo su rivista]
Schönlaub, Hans Peter; Ferretti, Annalisa
abstract

2015 - Wolayer Formation [Articolo su rivista]
Schönlaub, Hans Peter; Ferretti, Annalisa
abstract

2014 - Composition and significance of the Katian (Upper Ordovician) conodont fauna of the Vaux Limestone (“Calcaire des Vaux”) in Normandy, France [Articolo su rivista]
Ferretti, Annalisa; Messori, Andrea; Bergström, Stig M.
abstract

Study of new conodont collections from the Vaux Limestone exposed at its classical locality at Saint-Hilaire-la-Gérard in the Sées syncline, the conodont fauna of which was previously described in a preliminary way by Weyant et al. (1977, Un épisode calcaire ashgillien dans l'est du Massif armoricain; incidence sur l'âge des dépôts glacio-marins fini-ordoviciens. Comptes Rendus de l’Académie des Sciences, Paris, 284, Série D, 1147-1149), has provided significant new information about Late Ordovician conodonts from Normandy. A more precise age of this formation has been established based on an unexpectedly abundant conodont fauna of low diversity. Representatives of Amorphognathus, Hamarodus, Sagittodontina, Scabbardella and Eocarniodus are present and the fauna is referable to the middle Katian-lower Hirnantian A. ordovicicus Zone. Our study, the first illustrating Ordovician conodonts from Normandy, shows that the fauna is closely similar to middle Katian faunas from other parts of continental Europe and represents the Sagittodontina robusta-Scabbardella altipes biofacies of the Mediterranean Province.

2014 - Katian (Upper Ordovician) conodonts from Wales [Articolo su rivista]
Ferretti, Annalisa; Bergstrom, S. M.; Barnes, C. R.
abstract

Middle and upper Katian conodonts were previously known in the British Isles from relatively small collections obtained from a few localities. The present study is mainly based on 17 samples containing more than 17 000 conodont elements from an approximately 14-m-thick succession of the Sholeshook Limestone Formation in a road cut near Whitland, South Wales, that yielded a diverse fauna of more than 40 taxa. It is dominated by representatives of Amorphognathus, Aphelognathus/Plectodina and Eocarniodus along with several coniform taxa. Representatives of Decoriconus, Istorinus and Sagittodontina are reported from the Ordovician of UK for the first time. The fauna is a typical representative of the British Province of the Atlantic Realm and includes a mixture of taxa of North American, Baltoscandic and Mediterranean affinities along with pandemic species. Based on the presence of many elements of Amorphognathus ordovicicus and some morphologically advanced specimens of Amorphognathus superbus, the Sholeshook Limestone Formation is referred to the lower A. ordovicicus Zone. Most of the unit is also coeval with Zone 2 of the Cautleyan Stage in the British regional stage classification, and stage slice Ka3 of the middle Katian Stage in the global stratigraphical classification, an age assignment consistent with data from trilobites, graptolites and chitinozoans. The unusually large collection of M elements of Amorphognathus provides insight into the complex morphological variation in this element of some Katian species of this genus. The Sholeshook conodont fauna is similar to those of the Crug and Birdshill limestones, but differs in several respects from the slightly older ones from the Caradocian type area in the Welsh Borderland. Although having some species in common, the Sholeshook conodont fauna clearly differs from coeval Baltoscandic faunas and is even more different in composition compared with equivalent North American Midcontinent faunas.

2014 - Katian conodonts from the Portrane Limestone: the first Ordovician conodont fauna described from Ireland [Articolo su rivista]
Ferretti, Annalisa; Bergström, Stig M.; Sevastopulo, George D.
abstract

The Portrane Limestone, which crops out in a small inlier about 17 km north of Dublin, is one of the few significant carbonate units in the Ordovician of Ireland. Samples from this formation, which has long been famous for its diverse silicified shelly fauna, have produced a biostratigraphically diagnostic conodont fauna of more than 2200 specimens representing a total of 26 taxa. The Amorphognathus superbus and A. ordovicicus zonal conodont species have been documented. Our study, the first one illustrating diverse assemblages of Ordovician conodonts from Ireland, shows that this fauna, which represents the Hamarodus brevirameus-Dapsilodus mutatus-Scabbardella altipes biofacies, is strikingly similar to middle Katian (Stage Slice Ka3) faunas from Wales, England, and continental Europe. This age dating is consistent with that advocated based on shelly fossils. The Portrane Limestone was deposited in a volcanic arc environment off the Avalonian microcontinent and is now located southeast of the Iapetus suture across Britain and Ireland. The fact that the Portrane area was placed on the southeastern side of the Iapetus and relatively close to Wales and northern England but probably widely separated from North America, may at least partly explain why the Portrane conodont fauna differs in important respects from broadly coeval faunas from eastern North America and has much closer affinities with European faunas.

2013 - Composition and significance of the Katian (Upper Ordovician) conodont fauna of the Sholeshook Limestone in South Wales, UK [Articolo su rivista]
Ferretti, Annalisa; Bergstrom, S. M.; Barnes, C. R.
abstract

2013 - Data from: Katian (Upper Ordovician) conodonts from Wales. Dryad Digital Repository. [Articolo su rivista]
Ferretti, Annalisa; Bergstrom, STIG M.; Barnes, CHRISTOPHER R.
abstract

2013 - Late Ordovician conodonts from Great Britain [Abstract in Atti di Convegno]
Bergstrom, S. M.; Ferretti, Annalisa
abstract

2013 - Rings without a lord? Enigmatic fossils from the lower Palaeozoic of Bohemia and the Carnic Alps [Articolo su rivista]
Ferretti, Annalisa; Cardini, Andrea Luigi; Crampton, James S.; Serpagli, Enrico; David Sheets, H.; Štorch, Petr
abstract

Fossilized ring-like structures, whose function and taxonomic affiliation are enigmatic, were recovered for the first time from the Upper Ordovician of the Carnic Alps and the Silurian of Bohemia. These rings, already mentioned as minor constituents in previous conodont studies (e.g., Webers 1966; Bischoff 1973), were reported from the Palaeozoic of several regions in Europe and North America. Originally considered as inwardly accreted adhering discs of a benthic Hyolithelminth worm with a phosphatic tubular projection, they were later reinterpreted in relation to a putative crinoid epibiont or even as possible Scyphozoans. Despite a long debate, neither the function of the enigmatic Palaeozoic rings nor their taxonomic affiliation have been fully clarified.The study material, extracted with a standard technique in use for conodonts, consists of 235 elements from 16 stratigraphic levels in the Plöcken Formation (Carnic Alps, Cellon Section; Amorphognathus ordovicicus Biozone, Hirnantian, Ordovician) and in the Kopanina Formation (Bohemia, Mušlovka Quarry; Polygnathoides siluricus Biozone, Ludfordian, Silurian). To explore whether ring size and shape changed over time, we employed a novel combination of geometric morphometric approaches for outlines with no 'homologous' landmarks and showed that only size appreciably varied with an increase of ca. 20%.The emerging data from this study are consistent with the interpretation of the rings as an adhering structure of a benthic organism living on a relatively uniform hard substrate.

2013 - The Paleozoic Era(them) [Articolo su rivista]
Hubmann, B.; Ebner, F.; Ferretti, Annalisa; Histon, K.; Kido, E.; Krainer, K.; Neubauer, F.; Schönlaub, H. P.; Suttner, T. J.
abstract

2012 - Are there black shales and black shales? [Articolo su rivista]
Ferretti, Annalisa; M. J., Melchin; A., Negri
abstract

2012 - Associate Editor of “Comptes Rendus Palevol” [Direzione o Responsabilità Riviste]
Ferretti, Annalisa
abstract

2012 - Benthic foraminifera as indicators of hydrologic and environmental conditions in the Ross Sea (Antarctica) [Articolo su rivista]
Bertoni, Erica; Bertello, L.; Capotondi, Lucilla; Bergami, Caterina; Giglio, F.; Ravaioli, M.; Rossi, C.; Ferretti, Annalisa
abstract

This study, present data on benthic foraminiferal assemblages from four box cores collected in different areas of the Ross Sea during the 2005 oceanographic cruise in the framework of the Italian Antarctic Research National Programme (PNRA).

2012 - Bollettino della Società Paleontologica Italiana [Direzione o Responsabilità Riviste]
Ferretti, Annalisa
abstract

2012 - Editorial Notes [Articolo su rivista]
Ferretti, Annalisa; M., Balini
abstract

2012 - From black-and-white to colour in the Silurian [Articolo su rivista]
Ferretti, Annalisa; Cavalazzi, Barbara; Barbieri, Roberto; Westall, Frances; Foucher, Frédéric; Todesco, Rossana
abstract

Ironstones and iron-rich limestones regularly occur as components of time-specific intervals of the Palaeozoic as well as in younger times (Brett et al., this issue). Silurian sediments deposited at high latitudes along the peri-Gondwana border are characterized by black and white limestone and graptolitic shale sequences. Those in the Carnic Alps (southern Austria) additionally contain colourful pink to red limestones and ironstones. Laminated structures such as the (ferruginous)-coatings around skeletal fragments (mostly trilobites and some cephalopods and echinoderms) and stromatolitic features along discontinuity surfaces display dark red, green, white and brownish colours due to the presence of goethite,magnetite, hematite, chamosite, calcite and subordinate apatite. Confocal laser Raman microscopy and complementarymicroscopic analysis of these ferruginous laminated structures document the presence of carbonaceousmatter associatedwith fossilizedmicrobial structures in the formof stromatolites, filaments and coccoids, suggesting a microbial role in the colouring of the Silurian world of the Carnic Alps. Iron concentrations up to 30× that of matrix and surrounding non-ferruginous rocks suggest blooms of ironmicrobe activity in response to the time-specific occurrence of chemically charged sea water during global biotic events.

2012 - Looking towards the future [Articolo su rivista]
Ferretti, Annalisa
abstract

2012 - Rings without a lord? Enigmatic fossils from the Lower Paleozoic of Bohemia and the Carnic Alps. [Abstract in Atti di Convegno]
Ferretti, Annalisa; Cardini, Andrea Luigi; Crampton, James S.; Rigoni, Cecilia; Serpagli, Enrico; Sheets, H. David; Štorch, Peter
abstract

2012 - Time-specific aspects of facies: State of the art, examples, and possible causes [Articolo su rivista]
Brett, Carlton E.; Mclaughlin, Patrick I.; Histon, Kathleen; Schindler, Eberhard; Ferretti, Annalisa
abstract

The term “time-specific facies” (TSF) was introduced to the scientific community by the late Otto H. Walliser to refer to unique facies typical of particular narrow intervals, some of which were related to bioevents. In some senses, however, the concept was recognized much earlier and is even engrained in the very names of some geologic periods. The concept of time-specific facies is expanded slightly herein to include distinctive or unique regional to global characteristics of the sedimentary record that characterize particular intervals of geologic time. The recognition of time-specific and widespread processes in the sedimentary record is a critical step in unraveling the interplay between processes of differing scale. These range from very short-term, but widespread facies that overlap with event deposits, to general facies types that may persist for intervals up to 10s of millions of years in duration. This paper briefly summarizes the history of development of the TSF concept, provides examples to illustrate a few of the key aspects of time-specific facies and offers a few tentative explanations for this phenomenon. Among the factors that control TSFs, abrupt changes in redox conditions and early diageneticmineralization, sedimentary condensation, often associated with abrupt sea level change, altered climate and paleoceanography, and biotic evolution and extinction seem to be most critical and permit a preliminary genetic classification of TSFs. Inevitably, however, many TSFs reflect multiple effects and some remain largely unexplained.

2012 - Time-specific facies: The color and texture of biotic events [Articolo su rivista]
Ferretti, Annalisa; Histon, Kathleen; Mclaughlin, Patrick I.; Brett, Carlton E.
abstract

2012 - Time-specific facies: the colour and texture of biotic events [Curatela]
Ferretti, Annalisa; K., Histon; P. I., Mclaughlin; C. E., Brett
abstract

2011 - The Late Ordovician glacial event in the Carnic Alps (Austria). In GUTIÉRREZ-MARCO J.C., RÁBANO I. & GARCÍA-BELLIDO D. (Eds), Ordovician of the World [Capitolo/Saggio]
H. P., Schönlaub; Ferretti, Annalisa; L., Gaggero; E., Hammarlund; D. A. T., Harper; Histon, Catherine; H., Priewalder; C., Spötl; P., Štorch
abstract

2010 - Introduction [Time and life in the Silurian] [Articolo su rivista]
Corradini, Carlo; Ferretti, Annalisa; Storch, Petr
abstract

Introduction to the Thematic Volume

2010 - Time and Life in the Silurian. A multidisciplinary approach. Subcommission on Silurian Stratigraphy Field Meeting 2009, (Sardinia, June 4-11, 2009), Proceedings [Curatela]
C., Corradini; Ferretti, Annalisa; P., Storch
abstract

After about two years of hard work spent in planning and organizing the Conference “Time andlife in the Silurian: a multidisciplinary approach”, Field Meeting of the Subcommission on Silurian Stratigraphy, recently held in Sardinia in June 4-11, 2009, our effort has finally come to an end. The editing of the Conference Proceedings’ volume is now completed, as promised, within one-year by the end of the meeting. It has been a long but quite rewarding experience. The diverse papers here included are only apart of the multi-faceted contributions presented at the Conference sessions in Villasimius (Cagliari). Nevertheless, as also underlined by our Chairman, they reflect the multidisciplinary approach we strongly insisted on as a main topic when we proposed this meeting. We are firmly convinced that only by data integration and true comparison of results a real knowledge might effectively arise.This volume also offers a unique opportunity to expose our “special Silurian world” to non-Silurian or, more in general, to non-Palaeozoic people, and synchronize methods and approaches with those employed by specialists working in other time-slices. This has been possible thanks to the courtesyof the Società Paleontologica Italiana. Former President Ruggero Matteucci started with us this adventure accepting to reserve a volume of the Bollettino for our proceedings, present President Andrea Tintori gave us ample spaces to decide and allowed the download of pdf files at the Conference site. The Editorof the journal, Enrico Serpagli, kindly supervised our editorial efforts (but he is a Silurian-man, so it was not too hard to convince him). Furthermore, it is an occasion to make the Bollettino better known outside Italy, as most of the Silurian workers come from abroad. As usual tradition in a final phase of a project, it is also time of acknowledgements. First of all, this work has been made possible thanks to the precious support of reviewers who have made the real editorial work on the papers, with their accurate revisions, motivating criticism and addressed suggestions. We acknowledge their excellent contributions by naming them here: Bradley D. Cramer, Jiri Fryda, Lennart Jeppsson, Michael M. Joachimski, Markes E. Johnson, Jiri Kriz, Oliver Lehnert, David Loydell, Peep Männik, Michael J. Melchin, Ken T. Ratcliffe, Jia-Yu Rong, Mena Schemm-Gregory, Hans Peter Schönlaub, John A. Talent, Vojtech Turek and two anonymous reviewers. A great thank to single authors who have accepted our invitation in publishing in the BSPI and have strictly respected all editorial requests. Special thanks are also due to our respective families, who have tolerated us and our numerous changing moods of this last period. Finally, a message for the readers of the Bollettino della Società Paleontologica Italiana. They might find a slightly different target in this volume from the usual papers generally included in the journal. This is in the light of the new style of the Bollettino, hoping to find in a not too far future more and more multidisciplinary contributions reflecting the diverse souls of the palaeontological debate developing now in the world.

2009 - Cephalopod limestone biofacies in the Silurian of the Carnic Alps, Austria [Abstract in Atti di Convegno]
Ferretti, Annalisa; Histon, Catherine
abstract

Cephalopod limestones represent one of the most peculiar biofacies that developed in Silurian times along the northern margin of Gondwana. The presence and relative abundance of fossils, clearly visible in the field, enabled a taxonomic study of the main fossil groups since the end of the eighteenth century. Together with the most evident cephalopods, also bivalves, brachiopods and trilobites were studied in detail in different times. A good stratigraphic assignment either with graptolites or with conodonts was made of most sections. Paleoecological studies, on the contrary, were not so definite. Cephalopod limestones from North Gondwana are often referred to as a single unit, andthe same paleoecologic-environmental conclusions driven in an area are borrowed and extended to other regions. Key-stratigraphic sections (Rauchkofel Boden, Cellon, Rauchkofel Boden torl, Valentin Törl, Seewarte, Seekopf) representing distinctive paleogeographic/paleoenvironmental settings were taken into consideration and studied in detail in this work, paying particular attention to observe taphonomical information (abundance, dimension, orientation, colour, preservation, etc.) of all organisms composing the fauna. The study aimed to fit even the Carnic Alps cephalopod limestone biofacies into a more general picture of the Silurian. In particular, a precise depositional environment and an improved sequence-stratigraphical frame for the Silurian of the Carnic Alps in Austria based on a sedimentological, lithostratigraphical, biostratigraphical and microfacial approach was achieved (Brett et al., in press).Furthermore, analysis of “ooidal pockets” and “stromatolite-like” structures within the Pt. celloni – Pt. a. amorphognathoides conodont zones is also discussed with regard to their paleoenvironmental implications. Similar studies in other sectors (Oggiano & Mameli, 2006 from the Ordovician/Silurian of northern Sardinia), for this stratigraphical interval highlight that knowledge to date regarding these peculiar carbonate facies is still quitelimited. In-depth studies in key areas to recognise these markers may shed light on the relative positions of microterranes along the North Gondwana margin.REFERENCESBRETT C., FERRETTI A., HISTON K., SCHÖNLAUB H.P. Silurian Sequence Stratigraphy of the Carnic Alps, Austria. Palaeogeography, Palaeoclimatology, Palaeoecology (in press).OGGIANO G., MAMELI P. (2006). Diamictite and oolitic ironstones, a sedimentary association at Ordovician–Silurian transition in the north Gondwana margin: New evidence from the inner nappe of Sardinia Variscides (Italy). Gondwana Research, 9: 500-511.

2009 - Highly tectonized Silurian and Lower Devonian sediments at Funtanamare (SW Sardinia) [Capitolo/Saggio]
Pillola, G. L.; Ferretti, Annalisa; Corriga, M. G.; Corradini, C.
abstract

A very few trilobites have been found during the preparation of this stop. They are the first trilobites ever illustrated from the Silurian of Sardinia.

2009 - Laminated ferruginous deposits from the Silurian of Carinthia, Austria [Abstract in Rivista]
Ferretti, Annalisa
abstract

2009 - Late Ordovician-Early Silurian Faunal Response to Sea-Level Change: A Case Study from a Peri-Gondwanan Sector. [Abstract in Atti di Convegno]
Histon, Catherine; Ferretti, Annalisa
abstract

2009 - Loboliths (crinoids) and conodont biostratigraphy of the Genna Ciuerciu Section (SE Sardinia) [Capitolo/Saggio]
Corradini, C.; Ferretti, Annalisa; Corriga, M. G.; Serpagli, Enrico
abstract

The lobolith bearing horizon is assigned to the Oul. el. detortus conodont Zone in good stratigraphical agreement with other scyphocrinoid records in southeastern Sardinia (reported but not stratigraphically assigned by Jaeger, 1977 and Barca & Jaeger, 1990) and with the uppermost Silurian lobolith-horizon knownin Europe and in North Africa (Haude, 1972, 1992).

2009 - Organic geochemistry and paleoenvironment of the Early Eocene "Pesciara di Bolca" Konservat-Lagerstätte, Italy [Articolo su rivista]
Schwark, Lorenz; Ferretti, Annalisa; Papazzoni, Cesare Andrea; Trevisani, Enrico
abstract

Exceptional preservation of fossils in so-called Konservat-Lagerstätten requires specific depositional regimesexcluding disturbance of bottom sediments by either wave actions and currents or by benthic fauna. We heredescribe a depositionalmodel for the Eocene “Pesciara di Bolca” Konservat-Lagerstätte based on sedimentological,paleoecological, and detailed organic geochemical results. Sedimentswere deposited in a lagoonal-like basinwithstagnant bottomwaters located on an extended carbonate platform thatwas sheltered from open marinewatersby a submarine threshold. Run-off from nearby land areas provided nutrients to support an algal communitydominated by diatoms.No fossil diatomshells have been identified, but evidence for their presence is given by thehigh abundance of highly branched isoprenoids in extractable bitumens. Influx of terrigenous organic matter intothe lagoon occurred in particular during deposition of the basal fish-bearing level L1. Here not only plantmacrofossils, amber, spores and pollen but also the lipid composition indicated notable input of land plants via thepresence of n-C24 to n-C32 carboxylic acids, long-chain n-alkanes (n-C27, n-C29, n-C31) and angiosperm waxtriterpenoids. The redox regime in generalwas strongly reducing as evidenced by the high concentration of sulfurvs. organic carbon, excellent kerogen preservation as shown by high hydrogen indices, and lowpristane/phytanebut high phytane/n-C18 ratios. Thewater columnwas highly stratified with anoxic saline bottomand fresh surfacewaters. Euxinic conditionswith free reduced sulfur present in the photic zone could only be detected in sedimentsfrom the L1 horizon via traces of aromatic carotenoids derived from green sulfur bacteria (chlorobiaceae), whichutilize H2S in anoxygenic photosynthesis. The depositional regime is thus comparable to the lithographiclimestones of Solnhofen but based on biomarker evidence lacks the high salinities postulated for the latter.Biomarker composition indicates that best preservation conditions prevailed in the basal part of the studiedsection (0–7 m above datum) but declined upon deposition of the upper part. We interpret the body of thePesciara as a parasequence of the 4th order (0.01–0.5 Ma), with the lower part representing a relative sea-levellowstand and the upper part a relative sea-level highstand.

2009 - Organic-carbon rich sediments in the Palaeozoic: a different world? [Abstract in Rivista]
Ferretti, Annalisa; Negri, A.; Wagner, T.; Meyers, P. A.
abstract

2009 - Organic-carbon-rich sediments through the Phanerozoic: Processes, progress, and perspectives [Articolo su rivista]
Negri, Alessandra; Ferretti, Annalisa; Wagner, Thomas; Meyer, Phil A.
abstract

This Special Issue is comprised of two related components. First, we present a summary of the occurrences of organic-carbon-rich sedimentary sequences in the Phanerozoic geological record and our overview of the evolution and current status of understanding of how they accumulated. We note especially some of the new advances in the kinds of palaeoceanographic proxies that can be used and in the more refined explanations that have emerged from these advances. The second and greater part of the Special Issue consists of fourteen research papers that provide examples of the more detailed analyses of organic-carbon-rich sedimentary sequences that can be achieved with modern techniques and that can be elegantly interpreted by specialists in these techniques.

2009 - Organic-carbon-rich sediments through the Phanerozoic: Processes, progress, and perspectives (SPECIAL ISSUE) [Curatela]
A., Negri; Ferretti, Annalisa; T., Wagner; P. A., Meyer
abstract

The stimulus for this Special Issue emerged from a very successful topical session presented at the European Geophysical Union Meeting in Vienna, Austria, in April 2007. The very well attended (80–100 people) session addressed recent research advances in “Organic-carbon rich sediment through time: Past present and future, ocean and climate feedback” that included a large number of excellent oral and poster presentations. This session was the continuation of a project started in 2000 that has already yielded two well-received special issues of Palaeogeography, Palaeoclimatology, Palaeoecology. Both special issues present collections of contributions that deal with organic-carbon-rich marine sequences in different temporal windows, and both simultaneously emphasize new issues in research and reviews of existing concepts and models. The current volume forms a trilogy launched by the Special Issue “Paleoclimatic and Paleoceanographic Records in Mediterranean Sapropels and Mesozoic Black Shales” (Meyers and Negri, 2003) and continued by “Causes and Consequences of Marine Organic Carbon Burial Through Time” (Negri et al., 2006). These two volumes brought together the sapropel and black shale communities that had previously studied these organic-carbon-rich sequences separately. Moreover, their goal was to highlight the similarities and differences of these two kinds of interesting sediments, pointing to mergers of the knowledge acquired separately (e.g., Meyers, 2006).

2009 - Palaeozoic black shales: how much should we trust the Recent to reconstruct the Past? [Abstract in Atti di Convegno]
Ferretti, Annalisa; Negri, A.; Wagner, T.; Meyers, P. A.
abstract

Organic-carbon-rich sediments were widely deposited during multiple intervals of Mesozoic and Palaeozoic time or even earlier; on the contrary, sediments rich in organic carbon are today restricted to small areas along continental margins and have rarely accumulated during the Cenozoic. Global marine deposits document that episodes of accumulation of OC-rich sediments occurred in different regions and at different times.These episodes were linked to climatic and palaeoceanographic perturbations that resulted in massive fluctuations in hydrologic and nutrient cycles and in ocean chemistry and that recurred throughout geologic time.The whole Palaeozoic is punctuated by a profusion of episodes of black shale deposition that represent a common and not unusual sediment for that time. Furthermore, the abundance of organic matter does not, per se, imply black shales. The Palaeozoic, in fact, is also characterized by fossiliferous OC-rich limestones, e.g. the Silurian–Devonian “Orthoceras limestones” bordering northern Gondwana. However, the paucity of survivingPalaeozoic and earlier black shale sections makes it difficult to impossible to recognize the internal structure of global events that are common in younger OC-rich sedimentary sequences. Going ever deeper into the past, in fact, two factors appear playing a more and more fundamental role: preservation and time resolution. OC-rich sediments, either in form of black shales or limestones, do not necessarily reflect periods of elevateddeposition of high organic matter but may paradoxically simply represent times of better organic matter preservation. Then, even well-dated sequences do not offer the high resolutionrecords needed to fully document or delineate short-time processes. In the Palaeozoic the length of individual biozones is generally on the order of millions of years, which is in the same range as third-order sea-level changes. Thus, an important question in Palaeozoic sequences is whether episodes occur at different scales or belong to cycles of diverse order.Also according to this premise, too often was exasperate the use of the uniformitarianism principle in which models or opinions derived from recent examples are simplistically applied to any of the older “timeboxes”. In actuality, physical and biological conditions (e.g., oxygen and CO2) have strongly varied through time. Palaeozoic black shales were clearly deposited in a CO2-dominated setting (see Berner, 1994, 1998), whereas youngerdeposits reflect a lower concentration of the same gas. Again, the nature of primary producers is not yet completely defined for pre-Jurassic production of organic matter.Furthermore, palaeogeographic scenarios reveal completely different worlds in terms of land masses, oceans, palaeolatitudes, etc. According to this, any attempt to model the deposition of OC-rich sediments through the Phanerozoic must necessarily be tuned with all these variables. Another relevant point is that some of the Phanerozoic OC-rich sediments are defined as global events, like the Cretaceous OAE1a and OAE2, but some othersappear to have had a more restricted and even localized significance. These differences require the application of different approaches in search of possible interpretations and perhaps diverse mechanisms leading to the deposition of OC-rich sequences.Finally, many of the most significant black shale episodes in the Palaeozoic strictly match with major crises in the history of life. Understanding what drives global diversity may be used to explain processes, such as mass extinctions, that control diversity and turnover at a variety of geographic and temporal scales.The main issues described here need to be further investigated and are certainly worth answering. The Scientific Community must come to a multiple-time scale approach and to a constructive dialogue that better integrates data and models in order to be even more successful. These

2009 - Phanerozoic organic-carbon-rich marine sediments: Overview and future research challenges [Articolo su rivista]
Negri, Alessandra; Ferretti, Annalisa; Wagner, Thomas; Meyer, Phil A.
abstract

“One of the major obsessions of many early workers, to the mid-1900s, was the application of uniformitarian principles to depositional models for black shales“ (Arthur and Sageman, 1994).The purpose of this overview of organic-carbon(OC)-rich marine sediments is to provide a brief but current summary of the historical developments, principle concepts, and remaining challenges in integrated sapropel and black shale research. As such, it provides a substantive introduction to the Special Issue of Palaeogeography, Palaeoclimatology, Palaeoecology on “Organic Carbon Rich Sediments through the Phanerozoic: Processes, Progress, and Perspectives”. Given this focused scope, the overview does not aim to be comprehensive or complete but to provide a solid setting for the fourteen individual research papers that constitute this Special Issue and two previous special issues (Meyers and Negri, 2003; Negri et al., 2006) that cover research aspects complementary to this one. Like the individual contributions, this introduction and overview is organized into Cenozoic, Mesozoic, and Palaeozoic units. The Cenozoic and Palaeozoic units are deliberately larger than theMesozoic unit, acknowledging that much ground on Mesozoic black shale is already covered in the two previous special issues. Because the Late Cenozoic sapropels of the Mediterranean Basin have been extensively studied, understanding how these near-modern analogs of ancient black shales were deposited provides a good foundation for understanding how the older sequences may have evolved. In contrast, because far less is generally known about the black shales of the Palaeozoic than comparable OC-rich sequences of either the Cenozoic or the Mesozoic, a more comprehensive summary and comparison of the more ancient sequences is particularly appropriate to the theme of this Special Issue.

2009 - Sapropels in the Mediterranean Sea: do they really represent a modern analogue for black shales? [Abstract in Atti di Convegno]
A., Negri; Ferretti, Annalisa; T., Wagner; P. A., Meyers
abstract

2009 - Serpagli, celebrating his 44th Silurian-research birthday [Articolo su rivista]
Storch, Peter; Ferretti, Annalisa; Corradini, Carlo
abstract

The editors are pleased to dedicate this volume on the Silurian of Sardinia to Enrico Serpagli, an outstanding personality of Italian palaeontology, who devoted substantial part of his professional life to marine faunas and biostratigraphy of Ordovician and Silurian sedimentary formations mostly of southern Sardinia. Two of the editors are former doctoral students of Enrico Serpagli and PS has been collaborating with him since his first, early postgradual visit to Sardinia in 1982.

2009 - Silurian Palaeogeography of northern Gondwana: where was Sardinia at that time? [Articolo su rivista]
Ferretti, Annalisa; Oggiano, Giacomo; Corradini, Carlo; Storch, Peter
abstract

An unambiguous collocation of the actual European sectors in Silurian times is still far from accepted. The most recently published data appear to contradict and disprove current models. The position of Sardinia within this ill-defined scenario is still unclear.

2009 - Silurian conodonts from Sardinia: an overview [Articolo su rivista]
Corriga, Maria Giovanna; Corradini, Carlo; Ferretti, Annalisa
abstract

A general review of Silurian conodont data from Sardinia is here presented. Main features of the conodont associations, with special attention to their biostratigraphical implications, are briefly highlighted. All papers dealing with Silurian conodonts from Sardinia are listed, as well as a complete summary of productive localities is given in the appendix.

2009 - Silurian sequence stratigraphy of the Carnic Alps, Austria [Articolo su rivista]
Brett, Carlton E.; Ferretti, Annalisa; Histon, Kathleen; Peter Schönlaub, Hans
abstract

Sequence stratigraphy provides an alternative approach to correlation that may also serve as a predictive framework for the interpretation of sea-level and sedimentological change. The main aim of this study is to apply sequence stratigraphic concepts to the biostratigraphically well constrained shallow to moderately deep shelf carbonates and basinal graptolitic shale facies of the Silurian successions in the Carnic Alps of Austria in order to correlate the sequence packages and sea-level changes established there with those identified in other areas of North America and Europe. Documenting local sea-level curves is essential for determining global eustasy. The sea-level curve for the Silurian of the Carnic Alps has been elaborated within a refined stratigraphic framework for the Silurian based on conodont and graptolite biozonation [Melchin, M.J., Cooper, R.A., Sadler, P.M., 2004. The Silurian Period. In: Gradstein, F.M., Ogg, J.G., Smith, A.G. (Eds), A Geologic Time Scale. Cambridge University Press, Cambridge, pp. 188–201.]. In particular, the minor and frequent sea-level changes within the Silurian of the Carnic Alps are of special interest as these stratigraphic intervals are poorly preserved and not well studied in other Silurian localities. The interpretation of the field and microfacies analysis indicates major sequence boundaries in the Llandovery (3), Wenlock (3), Ludlow (3) and Přídolí–Lochkovian (2) which may be correlated with coeval disconformities in the Appalachian Foreland Basin of eastern North America and/or in the Welsh Basin of the British Isles. The following times appear to represent relative sea-level highstand maxima in the Silurian of the Carnic Alps, as indicated by dark, graptolitic shales in deep shelf to basinal carbonate-dominated sections: a) early Aeronian, approximately the Coronograptus cyphus graptolite Zone/Demirastrites triangulatus graptolite Zone), b) the early Telychian (Oktavites spiralis graptolite Zone; Pterospathodus celloni conodont Superzone), c) late Telychian (lower Pterospathodus a. amorphognathoides conodont Zone); d) early to middle Sheinwoodian (Kockelella ranuliformis to Ozarkodina sagitta rhenana conodont Zones; Monograptus riccartonensis graptolite Zones); e) mid-Wenlock ((?upper Kockelella walliseri conodont Zone; Cyrtograptus rigidus graptolite Zone); f) mid Homerian (Ozarkodina bohemica conodont Zone; Gothograptus nassa graptolite Zone); g) near the Wenlock–Ludlow boundary (Neodiversograptus nilssoni graptolite Zone); h) Polygnathoides siluricus conodont Zone; i) near the Ludlow–Přídolí boundary (upper Ozarkodina snajdri Interval Zone); j) lower Přídolí (Monograptus parultimus graptolite Zone) and k) at the Silurian–Devonian boundary (earliest Lochkovian: Icriodus woschmidti woschmidti conodont Zone. Of these, the earlier (at least b–e) are well represented in the Appalachian Basin, as in Avalonian sections in Great Britain and in Baltica. Johnson [Johnson, M.E., 2006. Relationship of Silurian sea-level fluctuations to oceanic episodes and events. GFF 128, 115–121.] documented eight major highstands in global sea-level during the Silurian. The temporal resolution obtained in the Carnic Alps for local sea-level changes allows for refinement of the Telychian to Přídolí sea-level curve, as the stratigraphic successions are chronologically well-defined using both conodont and graptolite biostratigraphy and K-bentonite levels. Nearly all inferred deepenings in the Carnic Alps section, with the exception of that in the Polygnathoides siluricus conodont Zone, approximately match highstands recorded on the Silurian sea-level curves of Johnson [Johnson, M.E., 1996. Stable cratonic sequences and a standard for Silurian eustasy. In: Witzke, B.J., Ludvigson, G.A., Day, J. (Eds.), Paleozoic sequence stratigraphy – Views from the North American Craton. Geol. Soc. Am. Spec. Pap. vol. 306, Boulder, pp. 203–212., Johnson, M.E., 2006. Re

2009 - The Cellon Section: a Review of the Stratotype Section for the Southern Alps (1894-2009) [Abstract in Atti di Convegno]
Histon, Catherine; Ferretti, Annalisa; Schönlaub, H. P.
abstract

Among the many geological sections located in the Central and Southern Alps the Cellon Section represents one of the most important as it serves as a reference section for the Upper Ordovician and the Silurian. There is no other profile which has beed visited so often or has attracted so many Earth scientists for basic or comparative studies. In fact, the long lasting history of research started with a mapping report of the area by Geyer (1894) which served as a basis for further studies. Geyer correlated the section with the upper Silurian in the former terminology of the 19th century. After the Great War scientistsfrom both Austria and Italy worked in the area. Of particular importance is the comprehensive study carried out by von Gaertner who focused his work on the Cellon section and introduced a formal lithostratigraphic subdivision which has partly been in use until the present. In the late 1950s Otto H. Walliser studied the conodont biostratigraphy for the Upper Ordovician, Silurian and lowermost Devonian portion of the Cellon Section.Based on more than 250 samples he collected almost 35,000 conodont elements which he assigned to 11 Silurian conodont zones. This zonation (Walliser, 1964) has served for many years as a standard for global correlation of Silurian strata. An Hirnantian conodont fauna has also now been documented (Ferretti & Schönlaub, 2001). In recent times, however, some additions and amendments from other sections have provided a more detailed zonation. Other studies on chitinozoans (Priewalder, 1997) and graptolites (Jaeger, 1975: Storch pers. comm. - presence of Glyptograptus persculptus) have added further important data so the section is now fully defined biostratigraphically using three standardarized zonations. Over the last four decades a variety of systematic palaeontologicalresearch by diverse authors has been carried out in the Cellon Section, e.g. on bivalves, brachiopods, nautiloids, graptolites, agglutinated foraminifers, ostracods, acritarchs, chitinozoans, trilobites and most recently even corals. Detailed studies have been done of the microfacies and faunal taphonomy in addition to studies of the sedimentology, geochemistry and application of C and O isotope analysis methods for the whole section.More recently, bentonite-bearing horizons in the Late Ordovician, upper Llandovery and Wenlock have been correlated with coeval occurrences in other parts of Europe. The ash layers originated from a subduction-related volcanism of an active plate margin and was dominated by calcalcalic mafic lavas of a volcanic arc setting with andesitic-rhyodacitic/dacitic magmatism, data of important significance with relation to geodynamics andpalaeogeographical reconstructions of the Peri-Gondwanan terranes (Histon et al., 2007).Finally, sequence stratigraphic methods were applied to the Silurian part of the Cellon Section by a team headed by Carl Brett which highlighted eustatic changes which may be traced across four palaeocontinents (Brett et al., in press).Present and Future - A valuable multidisciplinary data set is now available with regard to the Cellon Section which may be used for subdivision, to discriminate minute timelapses and to recognize short or long-lasting events in Earth’s history which occursimultaneously in other parts of the world. A short overview of the research done to date and present/future projects regarding faunal response to eustatic changes will be presented so as to highlight the still outstanding importance of this standard section.REFERENCESBRETT C.E., FERRETTI A., HISTON K. & SCHÖNLAUB H.P. (in press). Silurian sequence stratigraphy of the Carnic Alps (Austria). Palaeogeography, Palaeoclimatology, Palaeoecology.FERRETTI A. & SCHÖNLAUB H.P. (2001). New conodont faunas from the Late Ordovician of the Central Carnic Alps, Austria. Bollettino della Società Paleontologica Italiana, 40: 3-15.HISTON K., KLEIN P., SCHÖNLAUB H.P. & HU

2009 - The Perde Fogu outcrop: a classical exposure of Orthoceras limestone in the Fluminimaggiore area (SW Sardinia) [Capitolo/Saggio]
Ferretti, Annalisa; Corradini, C.; Kriz, J.; Piras, S.; Serpagli, Enrico
abstract

The Fluminimaggiore area has a special significance both for Sardinian palaeontology and Palaeozoic studies in Italy. Meneghini (1857) in fact just here illustrated nautiloids, bivalves and graptolites and Canavari (1899) reported ostracodes. The locality, discovered by General La Marmora in 1839, was originally named Cea Sant’Antonio (or Xea S. Antonio). The original outcrop was formed by displaced blocks of black limestone rolled downhill or collected and piled up by farm-workers in dry-stone walls along the paths close to the old cemetery of the village. The importance of Meneghini’s paper(Paléontologie de L’Ile de Sardaigne - 548 pages and 4 plates all describing Palaeozoic fossils) was only lately appreciated probably because it was included in the larger threevolumemonograph Voyage en Sardaigne edited by A. La Marmora.

2009 - The Silurian of Sardinia [Curatela]
Corradini, Carlo; Ferretti, Annalisa; Storch, Peter
abstract

The present volume “The Silurian of Sardinia” is composed of two related components. The first part comprises seven contributions introduced by an historical overview on the studies already carried out on the Silurian faunas of Sardinia. It aims to delineate a comprehensive scenario of the Silurian of Sardinia within a proper geological setting. A global overview regarding the palaeoenvironment and palaeogeography is also provided. The second part of the volume consists of seven research papers that illustrate actual knowledge on major fossil groups encountered in the Silurian limestones and shales of southern Sardinia.

2009 - The Silurian of Sardinia: facies development and palaeoecology [Articolo su rivista]
Ferretti, Annalisa; Storch, P.; Corradini, C.
abstract

Main features of the Silurian sequences exposed in Sardinia (Italy) are here described. Oldest sediments are represented by black shales, rich in graptolites, grading into a calcareous facies throughout the middle Silurian; however, the sequences exposed in the southeast and in the southwest are different, even if some similitude is evident. The spectacular variety of invertebrate fossils is briefly outlined and their environmental settings are discussed in the attempt of giving a contribution to the global picture of Silurian events.

2009 - The Silurian of Sardinia: introduction to the field trip [Capitolo/Saggio]
Corradini, C.; Ferretti, Annalisa; Storch, P.
abstract

The general features of the Silurian of Sardinia are briefly outlined, with special respect to the two main facies suites exposed in the southeastern and southwestern parts of theisland, respectively. An integrated biostratigraphical scheme with graptolite, conodont and chitinozoan zonations applied in the island is presented.

2009 - The Silurian of the External Nappes (southeastern Sardinia) [Articolo su rivista]
Corradini, Carlo; Ferretti, Annalisa
abstract

The most complete and best known Silurian succession of southeastern Sardinia is exposed in the Gerrei tectonic Unit. The Silurian sequence starts with Rhuddanian-lowermost Gorstian black graptolitic shales (Lower Graptolitic Shales), followed by a lower Gorstian-end Pridoli nodular calcareous unit (Ockerkalk). Graptolitic shales (Upper Graptolitic Shales) document the Lower Devonian. An integrated scheme of graptolite and conodont biozonation, compiled from Sardic data, is provided.

2009 - The Silurian of the Foreland Zone (southwestern Sardinia) [Articolo su rivista]
Corradini, C.; Corriga, M. G.; Ferretti, Annalisa; Leone, F.
abstract

The Silurian exposed in southwestern Sardinia is well-known for its precious faunal content. Lower part of the sequence consists of black graptolitic shales (Genna Muxerru Formation) comprising much of the Llandovery. It is suceeded by a calcareous unit (Fluminimaggiore Formation), locally rich in cephalopods, covering the rest of the Silurian. Even the Lower Devonian is represented by limestones. A precise and detailed biostratigraphical assignment of the units has been achieved by graptolites and conodonts.

2009 - The reference section of the Sardinian Ockerkalk: the Silius Section [Capitolo/Saggio]
Corradini, C.; Ferretti, Annalisa; Corriga, M. G.; Serpagli, Enrico
abstract

This locality has been stratigraphically studied mostly in the last decade (Barca et al., 1994, 1995; Serpagli et al., 1998). Together with the nearby Genna Ciuerciu Section, theSilius Section is a reference section for the Sardinian Ockerkalk, and, being the mostcomplete, it is candidate as stratotype of the unit as soon as it will be formally presented.This section is the type locality of two conodont taxa: Kockelella variabilis ichnusae Serpagli & Corradini and Pseudooneotodus bicornis contiguus Corradini. Furthermore it is one of the key-sections for the Silurian Conodont Zonation proposed by Corradini & Serpagli (1998, 1999).

2009 - Time and Life in the Silurian: a multidisciplinary approach - Field Trip Guide Book [Curatela]
C., Corradini; Ferretti, Annalisa; P., Storch
abstract

This volume is the field trip guide book of the International Subcommission on Silurian Stratigraphy Field-Meeting 2009 in Sardinia. The meeting consists of three days of scientific communications in the seaside village of Villasimius, in the southeastern part of the island, followed by a field trip in southern Sardinia.Several sections and localities to be visited in the four days trip are here presented and discussed. These localities are a good summary of the Silurian of Sardinia, and have been selected either for their historical relevance or the amount of available data; also the easy accessibility was considered. Furthermore, tobetter understand the Silurian successions of Sardinia, also one Hirnantian locality and two Lochkovian outcrops are described.A brief geological and stratigraphical overview of the Silurian of Sardinia introduces to the excursion itinerary with locality descriptions. More detailed information on the geology, stratigraphy and palaeontology of the Silurian of Sardinia is provided in the twin volume “The Silurian of Sardinia” publishedtogether with this guide book.The first two days of the trip are devoted to the well exposed, almost continuous sections of the External Nappe Zone (southeastern Sardinia); then the excursionparticipants will move to the External Zone (southwestern Sardinia), where the Silurian outcrops are less impressive, but the fossiliferous content is in general more exciting.

2008 - Eurytholia plates (Problematica) from the late Silurian of the Austrian Carnic Alps [Articolo su rivista]
Ferretti, Annalisa; Serpagli, Enrico
abstract

A small fauna of phosphatic plates of the enigmatic organism Eurytholia bohemica [Ferretti A., Serpagli E., Storch P., 2006. Problematic phosphatic plates from the Silurian-Early Devonian of Bohemia, Czech Republic. Journal of Paleontology 80 1026–1031.], is described for the first time from upper Silurian beds of Austria. Other known Silurian occurrences of this taxon were restricted to Bohemian localities even if the genus had been previously reported from several Ordovician outcrops. The extension of E. bohemica from the microcontinent of Perunica to that of Carnica suggests that Eurytholia was not an uncommon constituent of Silurian fauna, at least at intermediate latitudes in the southern hemisphere.

2008 - Silurian bioevents and sea-level change in North Gondwana: The response of pelagic faunas from the Carnic Alps (Austria). [Abstract in Atti di Convegno]
Histon, Catherine; Ferretti, Annalisa; H. P., Schonlaub
abstract

2008 - The conodont genus Teridontus (Miller, 1980) from the Early Ordovician of Montagne Noire, France [Articolo su rivista]
Serpagli, Enrico; Ferretti, Annalisa; Nicoll, Robert S.; Serventi, Paolo
abstract

THE CONODONT genus Teridontus was introduced in 1980 by Miller and was based on the Late Cambrian species Oneotodus nakamurai Nogami, 1967 from the Yencho Member of the Fengshan Fm. of northeast China. Teridontus was later reported from either the Upper Cambrian or Lower Ordovician (Landing et al., 1980; Miller, 1980; Landing and Barnes, 1981; Landing,1983; An et al., 1983, 1985; Ni et al., 1983; Peng et al., 1983; Nowlan, 1985; Landing et al., 1986; Bagnoli et al., 1987; An, 1987; Buggisch and Repetski, 1987; Pohler and Orchard, 1990; An and Zheng, 1990; Seo and Ethington, 1993; Wang, 1993; Lehnert, 1994; Nicoll, 1994; Seo et al., 1994; Ji and Barnes, 1994; Taylor et al., 1996; Lehnert et al., 1997; Jia, 2000; Dubinina, 2000; Pyle and Barnes, 2002; Zeballo et al., 2005) sediments in numerous localities around the world, but a unanimous interpretation of the composition of the Teridontus apparatus organization was far from accepted.

2007 - A new Early Ordovician conodont genus from southern Montagne Noire, France [Articolo su rivista]
Serpagli, Enrico; Ferretti, Annalisa; Vizcaino, D.; Alvaro, J. J.
abstract

Two species of a new Tremadocian (Early Ordovician) conodont genus from the Saint Chinian Formation of the southern Montagne Noire, France, are erected: Hammannodus sarae gen. et sp. nov. and Hammannodus juliae gen. et sp. nov. They were found within a single storm-induced limestone nodule interbedded with offshore shales belonging to the regional Shumardia (C.) pusilla (trilobite) Biozone, and to the Paltodus deltifer deltifer (conodont) Subzone. This conodont record is associated with the episodic development of carbonate productivity in temperate waters of the Montagne Noire platform, a process absent in neighbouring platforms of north-west Gondwana. The apparatus is composed of five coniform pyramidal elements occupying P and S positions and one bicostate element in the M position, having three or two sharp costae, respectively, with a subtriangular basal outline.

2007 - A review of the Late Cambrian (Furongian) palaeogeography in the western Mediterranean region, NW Gondwana [Articolo su rivista]
Alvaro, J. J.; Ferretti, Annalisa; GONZALEZ GOMEZ, C.; Serpagli, Enrico; Tortello, F. M.; Vecoli, M; Vizcaino, D.
abstract

The Cambrian–Ordovician transition of the western Mediterranean region (NW Gondwana) is characterized by the record of major erosive unconformities with gaps that range from a chronostratigraphic stage to a series. The hiatii are diachronous and involved progressively younger strata along the Gondwanan margin, from SW (Morocco) to NE (Montagne Noire). They can berelated to development of a multi-stage rifting (further North), currently connected to the opening of the Rheic Ocean, and concomitant erosion on southern rift shoulders. The platforms of this margin of Gondwana occupied temperate-water, mid latitudes and were dominated by siliciclastic sedimentation, while carbonate factories were only episodically active in the Montagne-Noire platform.The Upper Cambrian is devoid of significant gaps in the southern Montagne Noire and the Iberian Chains. There, the sedimentation took place in a transgressive-dominated depositional system, with common offshore deposits and clayey substrates, and was bracketed by two major regressive trends. The Late Cambrian is also associated with the record of volcanic activity (e.g., in the Cantabrian and Ossa-Morena zones, and the northern Montagne Noire), and widespread development of a tectonic instability that led to the episodic establishment of palaeotopographies and record of slope-related facies associations.Several immigration events are recognized throughout the latest Middle Cambrian, Late Cambrian and Tremadocian. The trilobites show a stepwise replacement of Acado-Baltic-type families (e.g., the conocoryphid–paradoxidid–solenopleurid assemblage) characterized by: (i) a late Languedocian (latest Middle Cambrian) co-occurrence of Middle Cambrian trilobite families with the first anomocarid, dorypygid and proasaphiscid invaders; (ii) a Late Cambrian immigration replacing previous faunas, composed of trilobites (aphelaspidids, catillicephalids, ceratopygids, damesellids, eulomids, idahoiids, linchakephalids, lisariids, onchonotinids, and pagodiids), linguliformean brachiopods (acrotretids, obolids, scaphelasmatids, siphonotretids, and zhanatellids), echinoderms (mitrates, glyptocystitid cystoids, and stromatocystoids), and conodonts belonging to the lower Peltura Zone; and (iii) the subsequent input of new trilobites (asaphids, calymenids, catillicephalids, nileids and remopleurids), which marks the base of the Proteuloma geinitzi Zone, associated with pelmatozoan holdfasts (Oryctoconus), and a distinct input of late Tremadocian conodonts (Paltodus deltifer Zone).The biogeographic distribution of latest Middle and Late Cambrian trilobites supports brachiopod data indicating strong affinities between the western Mediterranean region, East Gondwana (North China/Korea, South China, Australia, and Antarctica) and Kazakhstania during the late Languedocian, which became significantly stronger during the Late Cambrian. This major shift may suggest modification in oceanic circulation patterns throughout Gondwana across the Middle–Late Cambrian transition.

2007 - Carbon Accumulation and Organic Matter Preservation in the Pesciara Section (Bolca, Italy). [Abstract in Rivista]
Papazzoni, Cesare Andrea; Ferretti, Annalisa; Trevisani, E.
abstract

Exceptional fossilization in Fossil-Lagerstätten has been often explained with anoxic conditions allowing the preservation of organic matter. A long-lasting debate involves the genesis of sediments rich in organic matter, such as black shales and sapropels. Two main mechanisms have been proposed: 1) an increase in primary productivity; 2) an improved organic matter preservation in stagnant/anoxic basins. The geochemical investigation of the Early Eocene Fossil-Lagerstätte of Bolca (Italy) could help in the attempt to solve this problem. In fact, reversing the problem, if we guarantee taphonomic conditions of exceptional fossilization in anoxic settings, should we expect high contents of organic matter? Bolca is renowned worldwide for its extraordinarily preserved fish fauna. Most of the spectacular biota comes from fine-grained and evenly laminated limestones, up to 1 m thick. These “productive” layers are intercalated with storm-induced coarse-grained limestones rich in mollusks and foraminifera.Papazzoni & Trevisani (2006) recently dated the classic Pesciara Section of Bolca to the Early Eocene by means of Alveolina biozones and proposed a depositional model referring to a basin with restricted circulation and anoxic conditions on the bottom. To improve the model, some geochemical analyses were performed. The preliminary results are reported below.Total organic carbon concentration (TOC) has been measured for 13 samples from either the laminated (LL) or the coarse-grained limestones (CL). The organic matter content is usually lower than 0.5%, ranging between 0.16% and 0.49%, with 0.33% as mean value. An isolated maximum TOC content of 8.6% has been measured only in one sample from the lowermost fish-level, probably reflecting an episode of enhanced concentration of organic matter. The LL have TOC values only slightly higher than the intercalated CL. The TOC values measured in the Pesciara Section are comparable with those reported from other Fossil-Lagerstätten, such as Solnhofen (with TOC 0.2-0.9%; Hückel, 1974). These data demonstrate that exceptional fossil preservation and anoxic conditions are not necessarily coupled with high organic matter contents. Anoxia per se does not appear, therefore, to have had any direct effect on carbon accumulation or to have guaranteed high organic matter contents in the Fossil-Lagerstätte of Bolca.The δ13C isotopic composition of the Pesciara samples ranges between -23.98‰ and -26.66‰. Values of CL (mean -26.12‰) are significantly lighter than those of LL (mean -25.22‰). Organic matter C/N ratios vary between 33 and 48, with a mean value of 42.8 for LL and a mean value of 37.2 for CL. The general lack of variation in δ13C and C/N values between LL and CL suggests no significant changes in the source of the organic matter preserved in the Pesciara Section. Furthermore, these data would indicate a terrestrial origin for the organic carbon. References: Hückel, U., 1974, Vergleich des Mineralbestandes der Plattenkalke Solnhofens und des Libanon mit anderen Kalken. Neues Jahrbuch für Geologie und Paläontologie Abhandlungen 145: 153-182.Papazzoni, C. A. & Trevisani, E., 2006, Facies analysis, palaeoenvironmental reconstruction, and biostratigraphy of the “Pesciara di Bolca” (Verona, northern Italy): An early Eocene Fossil-Lagerstätte. Palaeogeography, Palaeoclimatology, Palaeoecology, 242: 21-35.

2007 - Eustasy and Basin Dynamics of the Silurian of the Carnic Alps (Austria) [Articolo su rivista]
Brett, C.; Ferretti, Annalisa; Histon, Catherine; Schonlaub, H. P.
abstract

2007 - Late Ordovician Ostracodes from Sardinia and Perigondwanan Ostracode Palaeobiogeography [Articolo su rivista]
Schallreuter, R.; HINZ SCHALLREUTER, I.; Ferretti, Annalisa; Serpagli, Enrico
abstract

A Late Ordovician ostracode fauna from Sardinia comprises more than 45 species of beyrichiocopes and podocopes. There is a total of 13 named new species of the genera Grammolomatella, Pseudulrichia, Antiaechmina, Postceratia, Arpaschmidtella, Bairdiocypridella, Prorectella, Dornbuschia, Velapezoides, Bairdia as well as of the new genus Sardicornina. The podocopes constitute about two thirds of all species, the binodicopes take three fourth of the beyrichiocopes. The fauna shows close relationships to faunas from both Thuringia and Central Iran (Yazd Block). The closest relations exist to Iran and the fauna of the so-called Bairdiocypridella clasts of the Thuringian Lederschiefer. Therefore, Thuringia, Sardinia and Central Iran can be regarded as a palaeobiogeographic ostracode province, here called the Thuringian province. Within Gondwana/Perigondwana two further ostracode provinces, the Armorican and Australian provinces can be distinguished.

2007 - The Eocene Fossil-Lagerstätte of Bolca (Italy): a guarantee of organic matter preservation? [Abstract in Atti di Convegno]
Papazzoni, Cesare Andrea; Ferretti, Annalisa; Trevisani, E.
abstract

Sediments rich in organic matter, best exempliﬁed by black shales and sapropels, represent unusual deposits in the fossil record. Special depositional conditions have been from time to time proposed to explain their genesis, invoking either an increase in primary productivity or an improved organic matter preservation in stagnant/anoxic basins. Within this controversy, Fossil-Lagerstätten may be useful towards providing a deﬁnite answer. In fact, reversing the problem, if we guarantee taphonomic conditions of exceptional fossilization in anoxic settings, should we expect high contents of organic matter? The early Eocene Fossil-Lagerstätte of Bolca (Italy) is renowned worldwide for its extraordinarily preserved ﬁsh fauna. The attention given to this site, known since the 16th century, has been almost exclusively focused on the study of the vertebrate fauna. Most of the spectacular biota come from ﬁne-grained and evenly laminated limestones, up to 1 m thick. These productive layers are intercalated with storm-induced coarse-grained limestones rich in molluscs and foraminifera. Papazzoni & Trevisani (2006) recently proposed a depositional model for the classic Pesciara Section of Bolca, referring to a basin with restricted circulation and anoxic conditions on the bottom. In order to better constrain the paleoecologic scenario, a geochemical investigation is currently in progress. The preliminary results are reported below.Total organic carbon concentration (TOC) has been measured for 13 samples from either the productive layers or the coarse-grained limestones. Most of the samples display organic matter contents lower than 0.5%, ranging between 0.l6% and 0.49%, with 0.33% as mean value. One sample from the lowermost ﬁsh-level has an isolated maximum TOC content of 8.6% most probably reﬂecting an episode of enhanced concentration of organic matter. TOC values of ﬁsh-layers are slightly higher than those measured in the intercalated storm deposits, but are still low. These values are comparable with TOC values reported from other stagnation-deposits of exceptional fossil content (e.g., Solnhofen with TOC 0.2-0.9%; Hückel, 1974). Therefore, exceptional fossilization in anoxic conditions does not appear to guarantee high organic matter contents. The δ13 C isotopic composition of the Bolca samples ranges between -23.98 per mil and -26.66 per mil. Values of bioclastic limestones (mean -26.12 per mil) are signiﬁcantly lighter than those of the productive layers (mean -25.22 per mil). Organic matter C/N ratios vary between 33 and 48, with a mean value of 42.8 for productive layers and a mean value of 37.2 for bioclastic layers. These values would indicate a terrestrial origin for the organic matter preserved in the Fossil-Lagerstätte of Bolca. References: Hückel, U., 1974, Vergleich des Mineralbestandes der Plattenkalke Solnhofens und des Libanon mit anderen Kalken. Neues Jahrbuch für Geologie und Paläontologie Abhandlungen 145: 153-182. Papazzoni, C. A. & Trevisani, E., 2006, Facies analysis, palaeoenvironmental reconstruction, and biostratigraphy of the “Pesciara di Bolca” (Verona, northern Italy): An early Eocene Fossil-Lagerstätte. Palaeogeography, Palaeoclimatology, Palaeoecology 242: 21-35.

2006 - La formazione di Uqua nella Sezione Valbertad (The Uqua Fm in the Valbertad Section) [Relazione in Atti di Convegno]
Bagnoli, G.; Corradini, C.; Ferretti, Annalisa; Serpagli, Enrico
abstract

N/A

2006 - Late Ordovician Ostracoda from Iran and their significance for palaeogeographical reconstructions [Articolo su rivista]
Schallreuter, R.; HINZ SCHALLREUTER, I.; Balini, M.; Ferretti, Annalisa
abstract

The first record of Late Ordovician ostracods from Iran comes from the lowermost part of the Shirgesht Formation east of Anarak, central Iran. The fauna comprises more than 40 species of beyrichiocopes and podocopes with a total of 17 new species and one new subspecies. Among the beyrichiocopes the Binodicopa are represented with 10 species, the Palaeocopa occur with eight species. The Anarak fauna shows relations to both allochthonous and autochthonous sediments from Thuringia as well as to Baltica with the relations being closest to the fauna of certain calcareous clasts of the glaciomarine Lederschiefer of Thuringia. The clasts have been considered as pebbles or boulders from debris flows (Schallreuter & Hinz-Schallreuter 1998), but their origin remained unclear until now. Investigation of the Anarak ostracods proved to be most significant in terms of clarifying this question. The close relations between both faunas suggest that the Thuringian clasts came from the vicinity of Gondwanian Iran.

2006 - Problematic phosphatic plates from the Silurian-Early Devonian of Bohemia, Czech Republic [Articolo su rivista]
Ferretti, Annalisa; Serpagli, Enrico; P., Storch
abstract

Problematic phosphatic elements are reported for the first time from Bohemia, Czech Republic, and are attributed to Eurytholia bohemica n. sp. Similar mineralized elements, interpreted as sclerites, were known only in a very narrow interval from Middle-Late Ordovician beds bordering the Iapetus Ocean. This new report comes from the Silurian and Early Devonian and provides a significant range extension for these Problematica as well as an enlargement of their geographic extent. Comments open new perspectives in the interpretation of these elements.

2005 - An updated Furongian stratigraphic framework for South-Western Europe [Articolo su rivista]
Alvaro, J. J.; Ferretti, Annalisa; GONZALEZ GOMEZ, C.; Pierre, C.; Serpagli, Enrico; Subias, I.; Vecoli, M.; Vizcaino, D.
abstract

Acta Micropaleontologica Sinica 22 (Supplement ), pp. 3-5.

2005 - Ooidal ironstones and laminated ferruginous deposits from the Silurian of the Carnic Alps, Austria [Articolo su rivista]
Ferretti, Annalisa
abstract

Distinct ooidal horizons and diverse laminated ferruginous structures are reported from the Silurian of the Carinthian Carnic Alps. The former were recovered in forms of centimetric horizons at the base of a single section (Rauchkofel Boden). The Carnic Alps reports are the only record in the Silurian from the European sector of the Northern Gondwana margin. Ooids consist mostly of chamosite, goethite and mixtures thereof with subordinate amounts of apatite. Laminated ferruginous deposits are present in themajority of the investigated sections and are represented either by rare “stromatolite-like” structures or by abundant banded iron-rich fossil coatings, mostly around trilobites and cephalopods. Both types are composed of calcareous laminae alternating with layers rich in iron silicates or oxides (chamosite, goethite, and magnetite). All these deposits can tentatively be regarded as microbial. Magnetite coatings revealed peculiar filaments of possible organic nature, closely resembling fungal hyphae.

2004 - Conchiglie, meraviglie di un mondo sconosciuto. [Curatela]
Ferretti, Annalisa; Papazzoni, Cesare Andrea; Lipparini, G.; Negra, O.; Padovani, Veronica; Vescogni, Alessandro
abstract

Guida in braille alla mostra omonima

2004 - Conchiglie-meraviglie di un mondo sconosciuto [Esposizione]
Russo, Antonio; Vescogni, Alessandro; Serventi, Paolo; Mazzanti, Marta; Bosi, Giovanna; Ferretti, Annalisa; Guioli, S.; Papazzoni, Cesare Andrea; Corradini, Domenico; Corradini, Elena; Padovani, Veronica; Leonardi, Giancarlo
abstract

Mostra dedicata al mondo delle conchiglie. La storia evolutiva dei molluschi dalla loro origine fino ai giorni nostri. Vengono esaminati tutti gli aspetti della tematica: paleontologia, paleoecologia, paleogeografia, mitologia, l'importanza alimentare e di costume

2004 - Eustasy and basin dynamics of the Silurian of the Carnic Alps (Austria) [Abstract in Atti di Convegno]
Brett, C.; Ferretti, Annalisa; Histon, Catherine; Schönlaub, H. P.
abstract

2004 - Ordovician to Lower Devonian of the Rauchkofel Boden Section [Articolo su rivista]
Ferretti, Annalisa; Histon, Catherine; H. P., Schönlaub
abstract

2004 - Surface-science approach to the study of mercaptobenzoxazole on Cu(100) [Articolo su rivista]
Di Felice, R; Ferretti, Annalisa; Mariani, Carlo; Betti, Mg; Baldacchini, C; Di Castro, V.
abstract

We present a combined approach, based on photoemission experiments and DIFT calculations, to the study of the adsorption of aromatic organic molecules on metal substrates. Our main purpose was to characterize the interface electronic properties and to search for electron states delocalized between the substrate and the molecular overlayer. We demonstrate how the interplay between theory and experiment, within a surface-science framework, is a powerful tool to gain insight into these issues. In particular, the computational results allow us to give a microscopic characterization, in terms of relative molecule-substrate coupling, of the photoemission peaks.

2004 - The Ockerkalk limestone (Late Silurian) from the Silius area: palaeobiological content and biostratigraphy [Relazione in Atti di Convegno]
C., Corradini; Ferretti, Annalisa; Serpagli, Enrico
abstract

2004 - Valentintörl Section [Articolo su rivista]
Histon, Catherine; Ferretti, Annalisa; H. P., Schönlaub
abstract

2003 - Silurian stratigraphy and paleogeography of Gondwanan and Perunican Europe [Capitolo/Saggio]
J., Kriz; J. M., Degardin; Ferretti, Annalisa; W., Hansch; J. C., GUTIERREZ MARCO; F., Paris; J. M. PICARRA D., Almeida; M., Robardet; H. P., Schonlaub; Serpagli, Enrico
abstract

2002 - A general view on the post-Sardic Ordovician sequence from SW Sardinia [Capitolo/Saggio]
F., Leone; Ferretti, Annalisa; W., Hammann; A., Loi; G. L., Pillola; Serpagli, Enrico
abstract

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 Gerrei tectonic Unit (SE Sardinia, Italy) [Capitolo/Saggio]
C., Corradini; Ferretti, Annalisa; Serpagli, Enrico
abstract

2002 - The Ockerkalk limestone in the Genna Ciuerciu Section [Capitolo/Saggio]
C., Corradini; Ferretti, Annalisa; Serpagli, Enrico
abstract

2002 - The Portixeddu Formation in the Punta Pedrona Section [Capitolo/Saggio]
F., Leone; W., Hammann; A., Loi; Ferretti, Annalisa; G. L., Pillola; Serpagli, Enrico
abstract

2001 - Biostratigrafia del Basamento Ercinico [Capitolo/Saggio]
Serpagli, Enrico; C., Corradini; Ferretti, Annalisa
abstract

2001 - New conodont data from the Late Ordovician of Central Carnic Alps (Austria) with report of a significant Hirnantian fauna [Altro]
Ferretti, Annalisa; H. P., Schönlaub
abstract

2001 - New conodont faunas from the Late Ordovician of the Central Carnic Alps, Austria [Articolo su rivista]
Ferretti, Annalisa; H. P., Schonlaub
abstract

Conodont faunas recovered from both the Uggwa and Wolayer limestones of the Central Carnic Alps, Austria documented unequivocally the Amorphognathus ordovicicus Zone. Hamarodus europaeus (Serpagli, 1967), Scabbardella altipes (Henningsmoen, 1948) and Walliserodus amplissimus (Serpagli, 1967) represent some of the characteristic species. The association closely matches in composition and age the conodont material described on the Italian side of the Alps. A younger fauna was recovered immediately above a well-known brachiopod Hirnantia Fauna in the Cellon section, a classic reference for Silurian conodont biostratigraphy. The association keeps a clear Ordovician aspect having its markers in A. cf. A. ordovicicus Branson and Mehl. 1933 and A. lindstroemi (Serpagli, 1967). Elements of "Dichodella-Birksfeldia", possibly corresponding to the distinctive North American Gamachian genus Gamachignathus, are well represented. Taxa previously common in colder regimes, such as Sagittodontina and Istorinus, are also present. The abundance and moderate diversity of this fauna, composed of about twenty species, allow a first significant definition of the Hirnantian conodont fauna from the Atlantic Faunal Region.

2000 - Caratteristiche e correlazione biostratigrafica degli “Ockerkalk” affioranti nella Sardegna sud-orientale (Siluriano sup.) [Capitolo/Saggio]
C., Corradini; Ferretti, Annalisa; Serpagli, Enrico
abstract

2000 - Europa im Paläozoikum [Capitolo/Saggio]
Serpagli, Enrico; Ferretti, Annalisa
abstract

2000 - La collocazione paleogeografica della Sardegna nel tardo Ordoviciano: nuovi dati [Capitolo/Saggio]
Ferretti, Annalisa; W., Hammann; Serpagli, Enrico
abstract

1999 - L'Europa durante il Paleozoico [Capitolo/Saggio]
Serpagli, Enrico; Ferretti, Annalisa
abstract

1999 - Late Ordovician conodont faunas from southern Sardinia, Italy: biostratigraphic and paleogeographic implications [Relazione in Atti di Convegno]
Ferretti, Annalisa; Serpagli, Enrico
abstract

Conodont faunas recovered from several localities in southwestern and southeastern Sardinia are assigned to the Late Ordovician on the basis of the recovery of Amorphognathus ordovicicus Branson and Mehl, 1933 and A. lindstroemi (Serpagli, 1967). A peculiar Amorphognathus species that has been found in slightly older sediments is described. 28 species belonging to 18 genera constitute the conodont collection; elements of Hamarodus europaeus (Serpagli, 1967) and Scabbardella altipes (Henningsmoen, 1948), together with those of Amorphognathus, numerically dominate the fauna. The same dominance was already reported in the 'Tonflaserkalk' of the Carnic Alps (Serpagli, 1967). Taxa of the genera Plectodina, Dichodella, Sagittodontina, Istorinus and Icriodina are described and discussed for the first time for Sardinia. The conodont fauna, composed at about 13000 elements obtained by the processing of about 550 kg of limestones, includes species typical of the Mediterranean Province. Nevertheless, the extreme paucity of its markers Sagittodontina robusta Knupfer, 1967 and Istorinus erectus Knupfer, 1967, which together represent less than one per cent, of the fauna, and the presence of other typical indicators of lower latitude affinity like Plectodina and Dichodella reveal the mixed character of Sardinian fauna. Together with the Carnic Alps, Sardinia probably occupied an outer position of lower latitudes (compared to the typical north-Gondwanian regions of the circumpolar belt) where faunistic interchange with both the British and Baltic provinces was possible.

1999 - Silurian Cephalopod Limestone sequence of the Cellon Section, Carnic Alps, Austria [Articolo su rivista]
Histon, Catherine; Ferretti, Annalisa; H. P., Schönlaub
abstract

1999 - The Silurian and Early Devonian of the Rauchkofel Boden Section, Southern Carnic Alps, Austria [Articolo su rivista]
Ferretti, Annalisa; Histon, Catherine; H. P., Schönlaub
abstract

1999 - The Upper Silurian sequence at the Valentintörl section [Articolo su rivista]
Histon, Catherine; Ferretti, Annalisa; H. P., Schönlaub
abstract

1998 - An Early Devonian section near Fluminimaggiore (Galemmu) [Articolo su rivista]
C., Corradini; Ferretti, Annalisa; Serpagli, Enrico
abstract

1998 - Cephalopod Limestone Biofacies, Carnic Alps, Austria [Capitolo/Saggio]
Ferretti, Annalisa; Histon, Catherine
abstract

1998 - Conodonts and biofacies from the Late Ordovician of Cannamenda (Bacu Abis) [Articolo su rivista]
Ferretti, Annalisa; Serpagli, Enrico; W., Hammann; F., Leone
abstract

Sardinia Fieldtrip Guide-book, ECOS VII

1998 - Conodonts from a Ludlow-Pridoli section near the Silius Village [Articolo su rivista]
Serpagli, Enrico; C., Corradini; Ferretti, Annalisa
abstract

1998 - Conodonts of the Late Cambrian section Prabetza near Villamassargia [Articolo su rivista]
Serpagli, Enrico; Ferretti, Annalisa; F., Leone; A., Loi; G. L., Pillola
abstract

1998 - Late Ordovician conodonts from Umbrarutta between Donigala and Lago Mulargia [Articolo su rivista]
Ferretti, Annalisa; Serpagli, Enrico; S., Barca; F., Leone
abstract

1998 - Late Ordovician conodonts from the Valbertad Section (Carnic Alps) [Articolo su rivista]
G., Bagnoli; Ferretti, Annalisa; Serpagli, Enrico; G. B., Vai
abstract

1998 - Outline of the post-Sardic Ordovician sequence in South-western Sardinia [Articolo su rivista]
F., Leone; Ferretti, Annalisa; W., Hammann; A., Loi; G. L., Pillola; Serpagli, Enrico
abstract

ECOS VII

1998 - The Ludlow-Pridoli Section “Genna Ciuerciu” west of Silius [Articolo su rivista]
C., Corradini; Ferretti, Annalisa; Serpagli, Enrico; S., Barca
abstract

Sardinia Field-trip Guide-book, ECOS VII

1998 - The Silurian and Devonian sequence in SE Sardinia [Articolo su rivista]
C., Corradini; Ferretti, Annalisa; Serpagli, Enrico
abstract

1998 - The Silurian and Devonian sequence in SW Sardinia [Articolo su rivista]
Ferretti, Annalisa; C., Corradini; Serpagli, Enrico
abstract

1998 - The late Ordovician section Cea Brabetza near San Basilio [Articolo su rivista]
Ferretti, Annalisa; Serpagli, Enrico; F., Leone; A., Loi
abstract

1998 - Upper Ordovician conodonts from the Prague Basin (Bohemia) [Articolo su rivista]
Ferretti, Annalisa
abstract

Late Ordovician conodonts from the Prague Basin are described and illustrated for the first time.

1998 - Wenlock and Pridoli conodonts from Argiola, East of Domusnovas [Articolo su rivista]
C., Corradini; Ferretti, Annalisa; Serpagli, Enrico
abstract

1998 - Wenlock-Ludlow conodonts from Perd'e Fogu (Fluminimaggiore) [Articolo su rivista]
Ferretti, Annalisa; C., Corradini; Serpagli, Enrico
abstract

1997 - Alle origini della vita (At the edge of life) [Articolo su rivista]
Ferretti, Annalisa; P., Vezzani
abstract

1997 - Cephalopod limestones [Articolo su rivista]
Ferretti, Annalisa; Histon, Catherine
abstract

1997 - Upper Ordovician conodonts from the Kalkbank of Thuringia (Germany) [Articolo su rivista]
Ferretti, Annalisa; C. R., Barnes
abstract

The Kalkbank limestone of Thuringia, Germany, occurs within a condensed clastic-oolitic sequence lying below deposits associated with the Hirnantian (Ashgill) glaciation. Conodonts were first reported from this unit by Knüpfer in 1967 but described only as morphospecies. On the basis of a new collection of over 25000 specimens, 13 species belonging to 11 genera are described. The discovery of M elements of Amorphognathus ordovicicus and A. ventilatus sp. nov. indicates an early Ashgill age for this limestone. Sagittodontina robusta, Scabbardella altipes and Istorinus erectus are the most abundant species; Hamarodus europaeus is also well represented. Taxonomic revisions are made for the first two species. The conodont fauna has a Mediterranean Province affinity and shows close relations with those from the Ashgill of Spain, France and Libya and, to a lesser extent, of the Carnic Alps and Sardinia.

1996 - Geological outline, community sequence and paleoecology of the Silurian of Sardinia [Articolo su rivista]
Ferretti, Annalisa; Serpagli, Enrico
abstract

Two distinct types of Silurian successions from Sardinia (Italy) are described and compared each other. Their age, faunal content and significance are briefly summarized in the attempt of giving a contribution to the global view of Silurian events.

1995 - Cephalopod limestone biofacies in the Silurian of the Prague Basin, Bohemia [Articolo su rivista]
Ferretti, Annalisa; Kriz, Jiri
abstract

The biostratinomy of Silurian cephalopod limestone biofacies of the Prague Basin is interpreted. Two facies types are recognized. One is the result of a surface current and the other one is the effect of redeposition within the current itself in a shallower environment during storm events. Orientation of cephalopod shells in these two facies types is discussed in relation to the Prague Basin development and to phenomena like telescoping, trap-structures and geopetal structures.

1995 - The Silurian and early Devonian in south-west Sardinia [Articolo su rivista]
Ferretti, Annalisa; M., Gnoli; J., Kriz; Serpagli, Enrico
abstract

1994 - Biofacies and palaeoenvironmental analysis of a limestone lens, unique in the Irish Silurian, from the Dingle Peninsula, County Kerry [Articolo su rivista]
Ferretti, Annalisa; C. H., Holland
abstract

A shallow-water environment, populated almost exclusively by benthic organisms, was periodically influenced by volcanic products. Synsedimentary tectonics, volcanism, and current activity were the main factors controlling sedimentation.

1994 - Conodont biostratigraphy of the Ockerkalk (Silurian) from southeastern Sardinia [Articolo su rivista]
Barca, Sebastiano; Corradini, Carlo; Ferretti, Annalisa; Olivieri, Renata; Serpagli, Enrico
abstract

Conodont faunas and related biostratigraphic implications from the Ockerkalk in the SIlurian of SE Sardinia are described and illustrated.

1993 - La bioturbazione. In: S. RAFFI & E. SERPAGLI, Introduzione alla Paleontologia [Monografia/Trattato scientifico]
Ferretti, Annalisa
abstract

1993 - Problematic microfossils from the Silurian of Ireland and Scotland [Articolo su rivista]
Ferretti, Annalisa; Holland, CHARLES H.; Syba, Erika
abstract

Problematic microfossils are described from the Silurian of the Dingle Peninsula, Country Kerry, Ireland and from a clast in the Old Red Sandstone Greywacke Conglomerate of the Midland Valley of Scotland. They are assigned to Sandvikina under the new specific name conica. The Irish material includes also single specimens of Sandvikina sp. and Regnellia camera. All these microfossils, which appear to be closely related, are here assigned to the new family Regnellidae, which on present evidence, is characteristic of the Silurian.

1992 - Biostratigrafia a conodonti del margine settentrionale del Gondwana (Ordoviciano sup.-Ashgill) [Monografia/Trattato scientifico]
Ferretti, Annalisa
abstract

1992 - Minor tectonic units within the Hercynian Arburese Nappe in Southwestern Sardinia. New structural and stratigraphic evidences [Capitolo/Saggio]
S., Barca; Ferretti, Annalisa; P., Massa; Serpagli, Enrico
abstract

1992 - The Hercynian Arburese Tectonic Units of SW Sardinia. New stratigraphic and structural data [Articolo su rivista]
Barca, Sebastiano; Ferretti, Annalisa; Massa, Paolo; Serpagli, Enrico
abstract

A complete geological frame is depicted for SW Sardinia.

1991 - First record of Ordovician conodonts from Southwestern Sardinia [Articolo su rivista]
Ferretti, Annalisa; Serpagli, Enrico
abstract

A rich conodont fauna from the Ordovician of Sardinia is described and illustrated.

1989 - Microbiofacies and constituent analysis of Upper Silurian-Lowermost Devonian limestones from Southwestern Sardinia [Articolo su rivista]
Ferretti, Annalisa
abstract

Main microbiofacies of the Silurian of Sardinia are described and illustrated.

Università degli studi di Modena e Reggio Emilia

Pubblicazioni