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Fontenais, Switzerland

Kocsis L.,University of Lausanne | Ozsvart P.,MTA MTM ELTE Research Group for Paleontology | Becker D.,Jurassica Museum | Ziegler R.,Staatliches Museum fur Naturkunde Stuttgart | And 2 more authors.
Geology | Year: 2014

Terrestrial climatic data reflect variable and often conflicting responses to the global cooling event at the Eocene-Oligocene transition (ca. 34 Ma). Stable isotopic compositions of the tooth enamel of large, water-dependent, herbivorous terrestrial mammals are investigated here to better understand the European continental climate during the late Eocene- early Oligocene. High δ18OPO4 and δ13C values reflect a semiarid climate and ecosystem in the late Eocene. In the west-southwest region of Europe, these conditions prevailed until at least 33 Ma, after which it became more humid. A similar change was recorded north of the Alpine thrust, but it occurred 2 m.y. earlier. The north and west-southwest regions show a significant offset in δ18OPO4 composition between 35 and 31 Ma, indicating the influence of different air trajectories with different moisture sources (Atlantic versus Tethys). This also marks the presence of an orographic height in central Europe from the latest Eocene. After 31 Ma, a large drop in δ18OPO4 is registered, explained by altitude-induced fractionation on meteoric water isotopic composition. The related paleoaltitude change is estimated to be 1200 m, and the uplift could have taken place along the Alpine-Dinaridic orogenic system. © 2014 Geological Society of America. Source

Bokma F.,Umea University | Godinot M.,EPHE Paris | Maridet O.,Jurassica Museum | Ladeveze S.,CNRS Center for Research on Palaeobiodiversity and Palaeoenvironments | And 6 more authors.
Systematic Biology | Year: 2016

Whether or not evolutionary lineages in general show a tendency to increase in body size has often been discussed. This tendency has been dubbed "Cope's rule" but because Cope never hypothesized it, we suggest renaming it after DepCrossed D signret, who formulated it clearly in 1907. DepCrossed D signret's rule has traditionally been studied using fossil data, but more recently a number of studies have used present-day species. While several paleontological studies of Cenozoic placental mammals have found support for increasing body size, most studies of extant placentals have failed to detect such a trend. Here, we present a method to combine information from present-day species with fossil data in a Bayesian phylogenetic framework. We apply the method to body mass estimates of a large number of extant and extinct mammal species, and find strong support for DepCrossed D signret's rule. The tendency for size increase appears to be driven not by evolution toward larger size in established species, but by processes related to the emergence of new species. Our analysis shows that complementary data from extant and extinct species can greatly improve inference of macroevolutionary processes. © 2015 The Author(s) 2015. Published by Oxford University Press, on behalf of the Society of Systematic Biologists. Source

Hugueney M.,University Claude Bernard Lyon 1 | Maridet O.,Jurassica Museum | Maridet O.,University of Fribourg | Mein P.,University Claude Bernard Lyon 1 | And 2 more authors.
Palaeobiodiversity and Palaeoenvironments | Year: 2015

Additional specimens of the poorly known African shrew Lartetium africanum (Lavocat, 1961) are described and complete our knowledge of this tiny animal. The results of this study justify the elevation of material originally described as a subspecies to the species rank. Soricids are hitherto unknown in older African localities. Like many other soricids, L. africanum lived in a rather humid habitat, close to a body of freshwater, as testified by the intercalations of travertines with reeds in the lacustrine lenses that yielded the fauna. However, the presence of associated vertebrate taxa also attest to more open environments in the surroundings and a tropical climate. Various hypotheses on the date of arrival of this taxon in Africa have been proposed since migration routes between Eurasia and Afro-Arabia were not always open during the Middle Miocene and also because magnetostratigraphic data are now known and can be compared. These hypotheses are discussed here. Recent advances in our knowledge of the palaeogeography and the comparison of L. africanum with western European Lartetium taxa suggest that Beni-Mellal could be older than previously proposed, possibly early Middle Miocene. © 2015, Senckenberg Gesellschaft für Naturforschung and Springer-Verlag Berlin Heidelberg. Source

Weidmann M.,Sentier du Molard 3 | Engesser B.,Naturhistorisches Museum | Berger J.-P.,Departement Des Science Of La Terre Of Luniversite | Ginsburg L.,Institute Of Paleontologie | And 2 more authors.
Revue de Paleobiologie | Year: 2014

This article presents a detailed palaeontological and biostratigraphical study of the lower freshwater Molasse (USM), Oligocene-earliest Miocene, located in Western Switzerland between the "Plateau vaudois" and the first anticline of the Jura Mountains. Recent data on mammals (based mainly on isolated teeth) and charophytes allow determining the age of these USM deposits, which ranges from the base of the Rupelian (MP20-21) to the early Aquitanian (MN1). The "Marnes rouges" Member (MP22-23) in the lower part of the series shows almost no outcrops in the studied area and remains to be investigated. Among the mammals, rodents (Rodentia) are best represented with, by order of abundance, Theridomyidae, Cricetidae, Eomyidae, Gliridae, Melissiodontidae, Sciuridae, Aplodontidae and Castoridae. Many other groups of small mammals are also present with lagomorphs, marsupials (Didelphidae), insectivores (Soricidae, Talpidae, Erinaceidae) and bats. The remains of large mammals are much more uncommon with plant-eaters such as perissodactyls (Rhinocerotidae : Molassitherium albigense, Rhinocerotidae indet.) and artiodactyls (Ruminantia : Iberomeryx sp., Bachitherium curtum, Bachitherium insigne, Mosaicomeryx quercyi ; Suidae indet. ; Cainotheriidae ; Dichobunidae ; Anthracotheriidae), as well as indeterminate carnivores. Concerning the charophytes, the first occurrence in the Oligocene (late Chattian, MP 28-30) of Stephanochara gr. praeberdotensis and Nitellopsis (Tectochara) ginsburgi is noteworthy because both taxa were considered so far to be restricted to the Miocene. Source

Scherler L.,Montpellier University | Tutken T.,Johannes Gutenberg University Mainz | Becker D.,Jurassica Museum
Quaternary Research (United States) | Year: 2014

Fossils of megaherbivores from eight late Pleistocene 14C- and OSL-dated doline infillings of Ajoie (NW Switzerland) were discovered along the Transjurane highway in the Swiss Jura. Carbon and oxygen analyses of enamel were performed on forty-six teeth of large mammals (Equus germanicus, Mammuthus primigenius, Coelodonta antiquitatis, and Bison priscus), coming from one doline in Boncourt (~80ka, marine oxygen isotope stage MIS5a) and seven in Courtedoux (51-27ka, late MIS3), in order to reconstruct the paleoclimatic and paleoenvironmental conditions of the region. Similar enamel δ13C values for both periods, ranging from -14.5 to -9.2‰, indicate that the megaherbivores lived in a C3 plant-dominated environment. Enamel δ18OPO4 values range from 10.9 to 16.3‰ with a mean of 13.5±1.0‰ (n=46). Mean air temperatures (MATs) were inferred using species-specific δ18OPO4-δ18OH2O-calibrations for modern mammals and a present-day precipitation δ18OH2O-MAT relation for Switzerland. Similar average MATs of 6.6±3.6°C for the deposits dated to ~80ka and 6.5±3.3°C for those dated to the interval 51-27ka were estimated. This suggests that these mammals in the Ajoie area lived in mild periods of the late Pleistocene with MATs only about 2.5°C lower than modern-day temperatures. © 2014 University of Washington. Source

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