Search results for "Biochronology"
showing 10 items of 17 documents
Ammonoids and quantitative biochronology - A unitary association perspective
2015
Ammonoid evolutionary changes have long been recognized to be excellent time markers. They are the major macrofossil group to date and correlate Paleozoic and Mesozoic marine strata. Originations and extinctions of ammonoid species are commonly used to define GSSPs and build high resolution biozonations. Biochronology is now an advanced field with the recent development of computerized, quantitative methods yielding robust biochronological schemes. It has been demonstrated that such quantitative biochronological methods are very efficient to resolve (often complex) biostratigraphic contradictions and produce accurate and high resolution biozonations, thus enabling precise dating and correla…
Reappraisal of ‘chronospecies' and the use of Arvicola (Rodentia, Mammalia) for biochronology.
2008
13 pages; International audience; The water vole, genus Arvicola, is characterised by a broad geographic distribution throughout Europe and is widespread during the late Middle and Upper Pleistocene. This genus is used as a major biostratigraphic tool within the Quaternary. Specific determinations using the Schmelzband-Differenzierung-Quotient or SDQ have identified many chronospecies within the fossil species Arvicola cantiana (Hinton, 1910). As SDQ calculation remains limited, this study reappraises the Arvicola genus in terms of morphodiversity and morphospace using outline analysis which takes into account the tooth as a whole. Outline analysis suggests that one single species of Arvico…
Considerations on an integrated biochronological scale of Italian Quaternary Mammals
2011
Viene analizzato il lavoro di MASINI e SALA (2007) sull’approccio integrato della distribuzione dei grandi e piccoli mammiferi dell’Italia continentale del tardo Pliocene e del Pleistocene, tenendo conto della nuova definizione del Quaternario, mettendo in risalto i punti di forza e quelli deboli della scala proposta. Vengono inoltre aggiunti nuovi dati sulla biocronologia a mammiferi del Pleistocene Superiore. The paper of MASINI and SALA (2007) regarding an integrated approach on the stratigraphic distribution patterns of large and small mammals in the late Pliocene and Pleistocene of the Italian peninsula is analysed, showing the weak and strong points. New data are presented on the mamm…
THE GARGANO TERRE ROSSE INSULAR FAUNAS: AN OVERVIEW
2010
After forty years from its discovery, the history of the field surveys and of the researches on the fossiliferous deposits on Gargano is briefly reported. The Gargano fauna belongs to the Abruzzo-Apulian Palaeobioprovince (including also Scontrone and Palena, Abruzzo). The fossil assemblage comprehends all the classes of terrestrial vertebrates: Reptilia, Amphibia, Aves and Mammalia. The faunal composition is unbalanced and presents the features of a typical insular endemic fauna. The bulk of the assemblage is composed of small mammals and birds. Based on literature, we report the most characteristic features, phylogenetic relationships, and evolutionary remarks on a list of mammals, focusi…
A new small mammal assemblage from the M013 Terre Rosse fissure filling (Gargano, South-Eastern Italy)
2013
Abstract The taxonomic study of the small mammal assemblage from fissure M013, sampled by a team of the University of Torino during the 2005–2009 excavations in the Dell’Erba Quarry (Apricena, Foggia) is presented. The assemblage includes the Echinosoricinae Apulogalerix cf. pusillus and the Crocidosoricinae ?Lartetium cf. dehmi; the Myomiminae species Stertomys simplex and Stertomys lyrifer; a new genus and species of Cricetodontinae and a single specimen of Hattomys cf. nazarii. Muridae include Mikrotia cf. parva, Mikrotia sp. 1 and a new genus and species of Murinae, phylogenetically related to Mikrotia. The occurrence of the new Murinae, the new Cricetodontinae, the two species of gliri…
New insular taxa from the oldest Terre Rosse fissure filling (Gargano, Southeastern Italy).
2012
A rich amount of fossil remains of a highly diversified vertebrate fauna, known as “Mikrotia fauna”, has been retrieved from the red soil deposits (Terre Rosse) which fill the extensive palaeokarst network that affects the Mesozoic limestone along the north-western slopes of Mount Gargano (Southern Italy). The faunal assemblages reveal a rather complex history of bioevents such as dispersals and extinctions, which occurred when the area was isolated. These reconstructions were based on the materials collected during the seventies and the eighties of the last century. Forty years after its discovery, the Gargano Terre Rosse finally yielded evidence of an older faunal settlement. The peculiar…
Mediterranean Neogene planktonic foraminifer biozonation and biochronology
2019
Abstract Planktonic foraminifera are widely used for biostratigraphy and correlation of Mediterranean Neogene marine sediments, and are a fundamental component in the astronomical tuning of the Neogene Time Scale. Recent developments in high-resolution studies, focused on the astronomical calibration of cyclically marine sediments cropping out in land-based sections and recovered from deep-sea successions, increased the accuracy of stratigraphic ranges of planktonic foraminiferal species improving the biostratigraphic resolution and biochronology. The large amount of data on planktonic foraminifera obtained through quantitative/semiquantitative analyses, published in the recent years, allow…
The Ventian mammal age (Latest Miocene): present state
2013
[EN] The Ventian land mammal age includes most of the Spanish faunas assigned to the biochronologic unit MN 13. It is correlatable with the Messinian, although it may include, in its latest part, Early Pliocene faunas. We propose that the Ventian begins with the fi rst occurrence of the Muridae genus Stephanomys (7 Ma, paleomagnetic dating from El Bunker, Teruel basin), well recorded in Teruel basin, and ends with the appearance of Promimomys (ca. 5 Ma), also registered in the Teruel basin. We suggest a new reorganization of the Ventian. The first subdivision corresponds to the zone M (Dam et al., 2001). The second, zone N, is proposed here for the first time, being equivalent to the zone w…
Pliocene-lower Pleistocene chronostratigraphy: A re-evaluation of Mediterranean type sections
1991
The Pliocene-Pleistocene stages defined for the Mediterranean region are generally used as the standard chronostratigraphic units for the upper Neogene and Quaternary. The recently developed calcareous plankton bio-chronology based on results from Ocean Drilling Program Leg 107 and numerous outcrop sections provides the necessary time control for evaluating the ages and stratigraphic relationships for the various Pliocene-Pleistocene stages and their associated stratotypes. Our results indicate that the currently accepted stratotypes do not provide a continuous stratigraphic representation for all of Pliocene-early Pleistocene time. On the basis of these findings, we propose a revised chron…
Lower Ovetian (Lower Cambrian) trilobites and biostratigraphy of the Pedroche Formation (Sierra de Córdoba, southern Spain)
2005
The low Lower Cambrian rocks from the Sierra de Cordoba, which consist of well exposed mixed facies and abundant fossil assemblages showing long stratigraphic ranges throughout the Pedroche Formation, represent one of the best successions of this age in Europe. The fossil assemblages include diverse Ovetian archaeocyaths, trilobites, small shelly fossils, calcimicrobia, trace fossils and stromatolites. Trilobites are still poorly known, and thus they are the main objective of this work. The trilobites studied originate from three sections. At the Arroyo de Pedroche 1 section, cf. Bigotinella and Bigotina bivallata are replaced towards the top by Lemdadella linaresae, Lemdadella perejoni sp.…