Daxner-Hock G.,Natural History Museum Vienna |
Badamgarav D.,Mongolian Academy of science |
Barsbold R.,Mongolian Academy of science |
Bayarmaa B.,Mongolian Academy of science |
And 14 more authors.
Palaeobiodiversity and Palaeoenvironments | Year: 2017
Cenozoic sediments of the Taatsiin Gol and TaatsiinTsagaan Nuur area are rich in fossils that provide unique evidence of mammal evolution in Mongolia. The strata are intercalated with basalt flows. 40Ar/39Ar data of the basalts frame the time of sediment deposition and mammal evolution and enable a composite age chronology for the studied area. We investigated 20 geological sections and 6 fossil localities of Oligocene and early Miocene deposits from this region. Seventy fossil beds yielded more than 19,000 mammal fossils. This huge collection encompasses 175 mammal species: 50% Rodentia, 13% Eulipotyphla and Didelphomorphia, and 12% Lagomorpha. The remaining 25% of species are distributed among herbivorous and carnivorous large mammals. The representation of lower vertebrates and gastropods is comparatively poor. Several hundred SEM images illustrate the diversity of Marsupialia, Eulipotyphla, and Rodentia dentition and give insight into small mammal evolution in Mongolia during the Oligocene and early Miocene. This dataset, the radiometric ages of basalt I (∼31.5 Ma) and basalt II (∼27 Ma), and the magnetostratigraphic data provide ages of mammal assemblages and time ranges of the Mongolian biozones: letter zone A ranges from ∼33 to ∼31.5 Ma, letter zone B from ∼31.5 to ∼28 Ma, letter zone C from ∼28 to 25.6 Ma, letter zone C1 from 25.6 to 24 Ma, letter zone C1-D from 24 to ∼23 Ma, and letter zone D from ∼23 to ∼21 Ma. © 2017, The Author(s).
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.
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.
Bokma F.,Umeå 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.
PubMed | EPHE Paris, CNRS Center for Research on Palaeobiodiversity and Palaeoenvironments, Royal Belgian Institute Of Natural Sciences, Umeå University and 2 more.
Type: Journal Article | Journal: Systematic biology | Year: 2015
Whether or not evolutionary lineages in general show a tendency to increase in body size has often been discussed. This tendency has been dubbed Copes rule but because Cope never hypothesized it, we suggest renaming it after Depret, who formulated it clearly in 1907. Deprets 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 Deprets 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.
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.
Woolly rhinoceros from the Late Pleistocene of Ajoie (Jura Canton, Switzerland) : Anatomical description and ecological implications [Rhinocéros laineux du Pléistocène supérieur dAjoie (Canton du Jura, Suisse) : Description anatomique et implications écologiques]
Becker D.,JURASSICA Museum |
Becker D.,University of Fribourg |
Dini M.,University of Fribourg |
Scherler L.,Section Darcheologie et Paleontologie |
Scherler L.,Montpellier University
Revue de Paleobiologie | Year: 2015
This article includes a detailed palaeontological and ecomorphological study of remains of woolly rhinoceros from the Late Pleistocene, discovered in Ajoie (Jura Canton, Switzerland). Based on comparative anatomy among late Quaternary Rhinocerotidae of Europe, the referred remains are attributed to the classical woolly rhinoceros Coelodonta antiquitatis. A detailed ecomorphological analysis shows a robust anatomical type and reveals a grass-dominated mixed feeder in open habitats. Also, a selective mortality of populations, dominated by breastfed juveniles and young adult and excluding old individuals, is observed on the basis of dental wear analysis. Within the local periglacial context in North Alpine domain, woolly rhinoceros from the Late Pleistocene of Ajoie seem to be in decline that could have resulted from interspecific competition, low ecological tolerance, probably to the seasonality, and/or social behaviour rather solitary or in small groups. These results observed at a regional scale could illustrate the mechanism of disappearance of woolly rhinoceros occurring in all Northern Eurasia during the terminal Late Pleistocene.
PubMed | University of Graz, Russian Academy of Sciences, Jurassica Museum and Natural History Museum Vienna
Type: | Journal: Scientific reports | Year: 2016
Central Asia is a key area to study the impact of Cenozoic climate cooling on continental ecosystems. One of the best places to search for rather continuous paleontological records is the Valley of Lakes in Mongolia with its outstandingly fossil-rich Oligocene and Miocene terrestrial sediments. Here, we investigate the response by mammal communities during the early stage of Earths icehouse climate in Central Asia. Based on statistical analyses of occurrence and abundance data of 18608 specimens representing 175 mammal species and geochemical (carbon isotopes) and geophysical (magnetic susceptibility) data we link shifts in diversities with major climatic variations. Our data document for the first time that the post-Eocene aridification of Central Asia happened in several steps, was interrupted by short episodes of increased precipitation, and was not a gradual process. We show that the timing of the major turnovers in Oligocene mammal communities is tightly linked with global climate events rather than slow tectonics processes. The most severe decline of up 48% of total diversity is related to aridification during the maximum of the Late Oligocene Warming at 25Ma. Its magnitude was distinctly larger than the community turnover linked to the mid-Oligocene Glacial Maximum.
Palaeontology and biostratigraphy of the Molasse of the oligocene and the earliest miocene in the talent and other localities of the "plateau vaudois" (Switzerland) [Paléontologie et biostratigraphie de la molasse de loligocène et du miocène basal du talent et dautres localités du plateau vaudois (Suisse)]
Weidmann M.,Sentier du Molard 3 |
Engesser B.,Naturhistorisches Museum |
Mojon P.-O.,Rue Girardet 68 |
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.