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Revision of the historical collections of Pliocene-Pleistocene large mammals from Le Riège and Saint-Palais localities, near Pézenas (Southern France)
Federica Mulè, Luca Pandolfi, Anne-Lise Charruault, Jean-Yves Crochet, Jérôme Ivorra, Fabrice Lihoreau, Laurent Marivaux, Mehdi Mouana, Félix Nesme, Céline Robinet, Philippe Münch and Pierre-Olivier Antoine
Keywords: Hérault; Mammalia; Montpellier; Neogene; Quaternary

doi: 10.18563/pv.48.1.e2
 
  Abstract

    Numerous “Quaternary” large-mammal fossils have been collected since the 1830s along the Le Riège stream, near Pézenas (Southern France). More than 120 specimens are stored in the collections of the Université de Montpellier (UM) under the name “Le Riège”. A major operation aiming at relocating the palaeontological collections of the University has made it possible to group together all the specimens of interest and launch their systematic revision for the first time. The fossils belong to the Reboul (1839; 51 samples) and de Christol (1865; 18 samples) Collections and 17 samples compose the Crochet & Ivorra Collection (1998). The remaining 38 samples have no mention about the exact time and location of their finding. We provide a critical inventory with literal transcription of inscriptions on specimens and historical labels. This revision confirms the presence of two distinct faunal assemblages under the name of “Le Riège”: Saint-Palais (Early Pliocene, MN14–15) and Le Riège sensu stricto (late Early Pleistocene, most likely MNQ19). The former assemblage, with coastal affinities, is composed of the ruminants Alephis sp. and Procapreolus cf. pyrenaicus, the rhinocerotid Pliorhinus megarhinus, the gomphotheriid Anancus arvernensis and marine mammals, all emblematic taxa for the Early Pliocene of Montpellier and Perpignan. The latter assemblage documents a late Early Pleistocene fluvio-volcanic sequence, yielding the bovid Bison (Eobison) spp., the cervid Eucladoceros cf. giulii, the hippopotamid Hippopotamus antiquus, the rhinocerotid Stephanorhinus etruscus, the equid Equus cf. altidens, and the elephantid Mammuthus cf. meridionalis, plus a few specimens of uncertain taxonomic affinities. This revision underscores the interest of revisiting historical collections and further provides a starting point for future research.
      


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S.I. Data
Les Tayassuidés des phosphorites du Quercy
Léonard Ginsburg
Keywords: Quercy Phosphorites; Tayassuidae
 
  Abstract

    Revision of the Tayassuidae from the old collections of the Quercy leads to interesting facts about taxonomic and phylogenetic problems. It could not have been well done without constant comparison with contemporaneous Tayassuidae from stratified series, as well as with European Miocene Tayassuidae and Hyotheriinae. The result is that only three species are present in the Phosphorites of Quercy: Doliochoerus quercyi FiLHOL (represented by two sub-species: the older, D. quercyi quercyi and the more recent, D. quercyi aquensis), Palaeochoerus gergorianus CROIZET et BLAINVILLE and Palaeochoerus purillus nov. sp. The two former species disappeared with Stampian time, while the third is the direct ancestor of the Aquitanian Palaeochoerus typus POMEL, which became extinct before the beginning of Burdigalian.

    The comparison with Hyotheriinae brought to light new criteria for determinations, based on the study of lower premolars. These observations are condensed in a table of keys for determinations.

    As a result of these studies, it came to light that the Suoidea of the Oligo-Miocene of Europe have never given rise to, except in rare cases, very long lineages. The different forms of pigs are replaced constantly in Europe by the simple game of extinctions and migrations. The reason of that discontinuity is considered here. 


  Article infos

Published in Vol. 06, Fasc. 1-2 (1974)

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A new hypothesis for the origin of African Anomaluridae and Graphiuridae (Rodentia)
Monique Vianey-Liaud and Jean-Jacques Jaeger
Keywords: Africa; Anomaluridae; Gliridae; Graphiuridae; Paleontology; PHYLOGENY; Rodentia
 
  Abstract

    A new hypothesis for the phylogenetic relationships of recent anomalurids and graphiurids is proposed, based on information from evolutionary lineages of Paleogene European rodents, particularly Gliridae, and Eocene Algerian Zegdoumyidae. Differences in first occurrences, in paleogeography, and in infraorbital structure in glirids (protrogomorphy and pseudomyomorphy) and graphiurids (hystricomorphy) separate Graphiuridae from Gliridae (Graphiurinae is here raised to family rank). Similar considerations, and dental morphology, suggest that Anomaluridae (appearing in the late Eocene) and Graphiuridae (appearing in the Pliocene) are related to early Eocene Zegdoumyidae. 


  Article infos

Published in Vol. 25, Fasc. 2-4 (1996)

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A new species of chimaeroid fish from the upper Paleocene (Thanetian) of Maryland, USA
Gerard R. Case
Keywords: Chimaeroid nov. sp.; Maryland; U.S.A.; Upper Paleocene
 
  Abstract

    The recent discovery of several mandibular toothplates of a chimaeroid fish at a dig in the area of the Landover Mall, near Landover, Prince Georges County, Maryland, brings to our attention a new species of the chimaeroid, Ischyodus.
     Although superficially reminiscent of the European chimaeroid toothplates of Ischyodus thurmanni (cf. text-fig. 2), I. williamsae nov. sp. probably has a more closer relationship to I. bifurcatus CASE, 1978, of the Upper Cretaceous of New Jersey and Delaware. 


  Article infos

Published in Vol. 21, Fasc. 1-2 (1991)

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Description des rongeurs Pliocènes de la faune du Mont-Hélène (Pyrénées-Orientales, France), nouveau jalon entre les faunes de Perpignan (Serrat-d'en-Vacquer) et de Sète.
Jean-Pierre Aguilar, Marc Calvet and Jacques Michaux
Keywords: Chronology; Climatology; France; Mont-Hélène; Pliocene; Rodents
 
  Abstract

    The Mont-Hélène's fauna [Pyrénées-Orientales, France], includes 15 species of rodents with a new one, Occitanomys montheleni n. sp. among the 9 species of the Murids which are listed. The uncommon Cricetid, Blancomys neglectus, is well represented in the fauna. Peculiarities of the population referred to Slephanomys cf. donnezaniare discussed. The locality a fissure filling may be the oldest one of Tabianian age known in Southern France. The diversity of the Murids gives evidence of a subtropical climate and of a diversified environment which may be linked to the spreading of the coastal plain following the filling up of the Roussillon Neogene Basin. 


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Published in Vol. 16, Fasc. 3 (1986)

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Lissamphibians from Dams (Quercy, SW France): Taxonomic identification and evolution across the Eocene-Oligocene transition
Alfred Lemierre and Maeva J. Orliac
Keywords: Eocene-Oligocene; Grande Coupure; Lissamphibia; Quercy Phosphorites

doi: 10.18563/pv.48.1.e3
 
  Abstract

    The locality of Dams (Quercy, southwestern France) has yielded two fossil assemblages, one from the late Eocene and another from the early Oligocene, making it one of the few localities with infillings across the Eocene-Oligocene transition. At least 24 taxa (13 mammals, 11 snakes) have been identified in this locality. Study of the lissamphibian remains from Dams yields an Eocene and an Oligocene assemblage, with a total of eight taxa. The Eocene assemblage includes two unnamed salamandrine species, one unnamed pelobatid species and one pyxicephalid species (Thaumastosaurus). The Oligocene assemblage includes two unnamed pleurodeline species, one salamandrine species (Salamandra sansaniensis) and an unnamed pelobatid species. Among the eight taxa from Dams, one Eocene salamandrine and one Oligocene pleurodeline are identified for the first time in the Quercy. A review of the lissamphibians from the Quercy area identifies eleven taxa for the Late Eocene (MP19) and eight taxa for Early Oligocene (MP22), with a major turnover at the Eocene-Oligocene transition. This turnover occurs in a time of major climatic changes, with a significant decrease in temperature and precipitation and concurrent increase in seasonality in Europe, likely affecting specialized taxa.
      


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Contributions à l'étude du gisement Miocène supérieur de Montredon (Hérault). Les grands mammifères. 5 - Les périssodactyles Equidae
Véra Eisenmann
Keywords: Equidae; Hipparion; Late Vallesian; Mammalia; Montredon; Perissodactyla
 
  Abstract

    Revision of the hipparion material from Montredon, including newly excavated and other unpublished specimens brings evidence of specific heterogeneity.
    A fragmentary very small MC III seems very close to H. macedonicum from the upper Vallesian of Ravin de la Pluie, Greece. In that same site was also found a large hipparion.
    Most of the Montredon material is referred to H. depereti. This species associates characters usually found in Vallesian hipparions (highly plicated upper cheek teeth, deep vestíbular grooves on the lower cheek teeth, robust metapodials) with characters more frequent in Turolian forms (middle size, lack of confluence in the upper premolar fossettes, lack of ectostylids on the adult lower cheek teeth, well developped keel on the MC III, facette for the 2nd cuneiform present on all MT III). H. depereti shares some of these characters with the Spanish and Portuguese hipparions transítional between the Vallesian and the Turolian (Masia del Barbo, Azambujeira) but is not identícal to any of them. The upper Vallesian hipparion material from Diavata, Greece, probably belongs to H. depereti but not the large hipparion rests from Ravin de la Pluie.
    Thus, Montredon and Ravin de la Pluie may well share the same small species, H. macedonicum, but they differ in the associated one: middle-sized H. depereti at Montredon, large-sized H. primigenium at Ravin de la Pluie. Both sites, however, give evidence of small hipparions during the Vallesian, coexisting with other larger species.
    The present paper also proposes an adaptation of the Kiesewalter's indices that calculates the height at the withers using the metapodial length, and discusses indices proposed by Gromova and by Sen et al. to express the relative development of the metapodial keel. 


  Article infos

Published in Vol. 18, Ext (1988)

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Rongeurs de l'Oligocène moyen provenant de nouvelles fouilles dans les phosphorites du Quercy
Monique Vianey-Liaud
Keywords: Oligocene; Quercy Phosphorites; Rodents; Theridomys

doi: 10.18563/pv.2.5.209-239
 
  Abstract

    A recent campaign of excavations (1965-68) undertaken by the Laboratoire de Paléontologie of Montpellier in pockets of the Quercy phosphorites, has permitted the dating of several localities thanks to the analysis of their micromammalian fauna.
    The rodents of localities belonging to the middle Oligocene (La Sauvetat zone) are the object of this study. This rodent fauna has been compared to the forms coming from three stratified localities belonging to the biochronologic zone of La Sauvetat :  Balm, Montalban and Lovagny.
    The abundance of material, notably of theridomyids and cricetids, permitted a summary statistical study to be effected and gave some precise details on the variability of the species (Theridomys varians in particular). Other details were provided on certain groups, notably on the upper teeth of Scíuromys cayluxi and on the milk teeth of theridomyids. Some specimens of «Sciurus» sp. and of Plesispermophilus angustidens were collected. By this means, it has been possible to establish, for the first time, a precise upper limit to the epoch of their appearance in Europe. 


  Article infos

Published in Vol. 02, Fasc. 5 (1969)

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Les traces de pas de Dinosaures et autres Archosaures du Lias inférieur des grands Causses, Sud de la France
Georges Demathieu, Georges Gand, Jacques Sciau, Pierre Freytet and Jacques Garric
Keywords: Dinosauroid footprints; France; Grands-Causses; Hettangian; ichnostratigraphy; paleoenvironments; Sinemurian; statistical results

doi: 10.18563/pv.31.1-4.1-143
 
  Abstract

    The Causses" is a near 3400 km2 large plateau located in the south of France. Here the first dinosaur footprints where found in 1935. After this, this area has yielded an ever-increasing number of ichnites now in excess of 500 specimens. These latter, 15 to 50 cm long, tridactyl or tetradactyl footprints of generally biped animals, were discovered at the surface of Hettangian to lower Sinemurian dolomite layers within 4 distinct stratigraphic units. The 35 sites bearing ichnites are located on the plateau margin. For the first time, morphologic characters studied through descriptive statistic methods with the usual parameters and classical Student and Snédecor tests, allowed us, to divide the whole set of biped traces into 6 ichnospecies. Their definitions are further constrained by multivariate statistical results using Principal Component Analysis (PCA), Factor Analysis of correspondances (FAC) and Discriminant Analysis (DA). All have confirmed the morphologic observations. So that now, the following taxa are identified : Grallator variabilis, G. lescurei, G. sauclierensis, G. minusculus, Eubrontes giganteus, Dilophosauripus williamsi, cf. Moraesichnium, Orníthopus fabrei nov ichnosp. The more immediately visible differences relate to the interdigital II-IV divarication and the digit length ratio. To this panel, we must add Batrachopus deweyi and shapes suggesting Trisauropodichnus and/or Anomoepus. Among all ichnite associations described in the lower Liasic, the New England assemblage presents the most affinities with ours. It shows the ichnotaxa Grallator, Dilophosauripus, Eubrontes, Batrachopus without forgetting Ornithopus fabrei nov. ichnosp. which is close to Ornithopus gallinaceus from the Massachusetts and Connecticut basins. On comparing the present early Jurassic ichnofauna of the Causses with the ones of the Middle and Upper Triassic formations of the eastem border of the Massif Central (France), it appears that tridactyl footprints become more and more numerous and large from Triassic to Early Jurassic. In the Causses, these latest are prevalent but in Quercy (France), Poland, Italy, USA, they are also associated with Omithopoda, Thyreophora and Sauropoda ichnites. Footprint areas considered here were generaly under an arid climate. Animals that passed by were heavy and bulky possible Megalosaur trackmakers, and lighter and slender Coelophysids or Ceratosaurs. For all, these areas were pathways as the orientations of the trackways seem point out. The directions followed by these reptiles were without any important variation during the Hettango-Sinemurian stages. These areas were also used from time to time by Crocodilomorpha and may be tetradactyl (I-IV) bipedal avian Theropods. However, the number of such trackways in sites, sometimes substantial, should not lead us to overestimate the trackmakers populations. These last were probably relatively moderately abondant in this inter-supratidal swamp environment. In the Causses, ichnites are connected with former algo-laminated deposits (Algal mats) which were rapidly hardened by means of calcitisation of cyanobacteria. The result has been a moderate depth of footprints; autopodia disturbing only a few cm of the carbonate substrate. Other fossils have been discovered : invertebrates with thin bivalve and gastropod shells, crustaceans tests and plants. These latter suggest the existence of paleomangroves like environments but also continental vegetation periodically overruning the swamp environment during regression/transgression cycles. At these times, wooded parts of it, could become protecting, feeding, resting and nesting places.

      


  Article infos

Published in Vol. 31, Fasc. 1-4 (2002)

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Contributions à l'étude du gisement Miocène supérieur de Montredon (Hérault). Les grands mammifères. 8 - Analyse paléoécologique de la faune mammalienne
Serge Legendre
Keywords: France; Mammalia; Montredon; Paleoecology; Upper Miocene
 
  Abstract

    The species diversity of the mammalian fauna from Montredon (Hérault, France, late Miocene) is examined in terms of richness and abundance. A cenogramic analysis of the fossil mammalian community suggests the prevalence of open habitats, with the presence of marshes and of a poorly developed galery forest, and a climate rather warm and dry. 


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Published in Vol. 18, Ext (1988)

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Additions of the Geiseltal mammalian faunas, Middle Eocene: Didelphidae, Nyctitheriidae, Myrmecophagidae.
Gerhard Storch and Hartmut Haubold
Keywords: Edentata; Geiseltalian; German Democratic Republic; Lipotyphla; Marsupialia; MP 11-13
 
  Abstract

    New and hitherto unpublished mammals from the stratigraphical levels Unterkohle, Untere Mittelkohle and Obere Mittelkohle of the Geiseltal near Halle, GDR, are described (= biochronological levels MP 11-13, Geiseltalian sensu Franzen & Haubold 1986a, b). The marsupial taxa Amphiperatherium aff. maximum (MP 12), A. goethei (MP 12), and Peratherium aff. monspeliense (MP 12 and 13) are recorded for the first time. A lectotype for Amphiperatherium giselense is designated, and the alleged primate Microtarsioides voigzi is assigned to Marsupialia, incertae sedis. A new insectivore species, Saturninia ceciliensis n. sp., is described (MP 13). The anteater Eurotamandua joresi is recorded for the first time outside its type locality, Grube Messel, FRG (MP 11). The present humerus and ulna display the autapomorphic features of the myrmecophagids. 


  Article infos

Published in Vol. 19, Fasc. 3 (1989)

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Les nouvelles faunes de rongeurs proches de la limite mio-pliocène en Roussillon. Implications biostratigraphiques et biogéographiques
Jean-Pierre Aguilar, Jacques Michaux, Bernadette Bachelet, Marc Calvet and Jean-Pierre Faillat
Keywords: Arvicolidae; Cricetidae; Gliridae; Miocene; Muridae; Pliocene; Rodents; Southern France
 
  Abstract

    Three new fossiliferous localities, two of karstic origin, Castelnou 3 and Font Estramar, respectively Late Upper Miocene and Lower Pliocene, and one of lacustrine origin, Thuir, Lower Pliocene, add data about the transition between Miocene and Pliocene faunas of rodents in southern France. An unexpected association of taxa was present in the late Upper Miocene, including between others, Myocricetodon, Hispanomys, Ruscinomys, Cricetus barrierei, Promimomys and a new species of Stephanomys, S. dubari nov. sp. Myocricetodon is still known in the Lower Pliocene. It is shown that the large field-mice known since the Late Upper Miocene belong to two different lineages, on one side, A. jeanteti, on the other side, A. gudrunae followed by A. gorafensis. Biochronological and biogeographical implications are discussed. 


  Article infos

Published in Vol. 20, Fasc. 4 (1991)

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Long-term fidelity of megaoolithid dinosaurs to a large breeding-ground in the Upper Cretaceous of Aix-en-Provence (southern France).
Géraldine Garcia, Yves Dutour, Isabellle Cojan, Xavier Valentin and Gilles Cheylan
Keywords: Large nesting ground; megaloolithid eggs; Southern France; Upper Cretaceous
 
  Abstract

    We present here the preliminary results from a new nesting site "Sextius-Mirabeau", discovered close to the historical centre of Aix-en-Provence in Upper Cretaceous deposits. This extensive megaloolithid nesting ground, the first large scale excavation (3225 m²) in France, yielded more than 530 eggs, some organized in clusters. Their study reveals the reproductive strategy of the megaloolithid egglayer group which indicates nesting fidelity and gregarious behaviour.  


  Article infos

Published in Vol. 32, Fasc. 2-4 (2003)

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Les rongeurs de l' Eocène inférieur et moyen d'Europe Occidentale; Systématique, phylogénie, biochronologie et paléobiogéographie des niveaux-repères MP 7 à  MP 14.
Gilles Escarguel
Keywords: Biochronology; Early and Middle Eocene; Gliridae; Ischyromyidae; Mammalia; MP Scale; New Genus and Species; Palaeogeography; PHYLOGENY; Rodents; Theridomyidae; Western Europe
 
  Abstract

    Fourteen distinct phyletical lineages which belong at least in three families: Ischyromyidae ALSTON, 1876, Gliridae THOMAS, 1896 and Theridomyidae ALSTON, 1876, have been identified after the study of more than 3600 rodent dental remains from about twenty Early and Middle Eocene european localities. A systematical and phylogenetical revision of these rodents has been achieved. Nearly all the specific and generic diagnosis are emended. Several new combinations and synonymies are proposed. Four new species and two new genera, Euromys nov. (Ailuravinae) and Hartenbergeromys nov. (Microparamyini), are named and described. Euromys nov. gen. is known by three distinctive ypresian (MP 7 to MP 10 european reference levels) chronospecies. This new lineage is thought to be the direct ancestor of Meldimys MICHAUX, 1968 and Ailuravus RUTIMEYER, 1891. A new species of the genus Plesiarctomys BRAVARD, 1850, Pl. lapicidinarum from Condé-en-Brie (MP 8-9 reference level), allows to relate the Plesiarctomys lineage to the Pseudoparamys MICHAUX, 1964 one. The taxa Sparnacomys HARTENBERGER, 1971, Pantrogna HARTENBERGER, 1971, and Corbarimys MARANDAT, 1989 are erected to genus rank; the last one is not thought to be an Ischyromyidae. A new chronospecies of Pantrogna, P. marandati nov. sp. from the locality of Prémontré (MP 10 reference level), is described. This lineage is at the origin of two others, namely Masillamys TOBIEN, 1954, including M. mattaueri (HARTENBERGER, 1975) nov. comb. (MP 10 reference level), and Hartenbergeromys nov. gen., known from MP 10 (H. hautefeuillei nov. sp.) and MP 11 (H. parvus TOBIEN, 1954) reference levels. The phylogenetical position of Hartenbergeromys nov. gen., at the origin of the european family Theridomyidae, is discussed. The systematical and phylogenetical status of two probable Paramyinae, "Paramys" woodi MICHAUX, 1964 and an unnamed genus and species, are discussed. New populations of the primitive Gliridae Eogliravus HARTENBERGER, 1971 and of the primitive Theridomyidae Protadelomys HARTENBERGER, 1968, are described and assigned to previously known species.

      


  Article infos

Published in Vol. 28, Fasc. 2-4 (1999)

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Mammals and stratigraphy : the Paleocene of Europe
Donald E. Russell, Jean-Louis Hartenberger, Charles Pomerol, Sevket Sen, Norbert Schmidt-Kittler and Monique Vianey-Liaud
Keywords: Europe; Mammalia; Mammalian biochronology; Paléogène; Stratigraphy
 
  Abstract

    The mammalian faunas of the Paleogene of Europe and their localities are reviewed with comments on problems of European stratigraphy (epoch, stage and substage limits) and on the possibilities of faunal migrations. Radiometric dating is discussed. A stratigraphic scale for the Paleogene is presented, as well as a refined system of sequential faunal levels. 


  Article infos

Published in Vol. 12, Ext (1982)

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Les poissons crétacés et tertiaires du bassin des Iullemmeden (République du Niger)
Henri Cappetta
Keywords: Actinopterygians; Cenozoic; Cretaceous; Dipnoans; Selachians
 
  Abstract

    The present work is devoted to the study of the Cretaceous and Tertiary fishes (teeth of Selachians, Actinopterygians and Dipnoans) collected during a recent expedition in Niger. The Maestrichtian localities have yielded a new genus and a new subspecies of Selachian: Igdabatis sigmodon nov. gen., nov. sp. and Lamna biauriculata nigeriana nov. subsp. The locality of Sessao, which has been attributed to the Thanetian by means of the study of the fish, has furnished by screen-washing an interesting fauna wherein six new species are described: Raja Iouisi, Dasyatis sessaoensis, D. sudrei, D. russelli, Hypolophites thaleri and Ceratodus casieri. Comparison of these faunas with contemporary faunas of Africa has brought out a certain endemism in the Iullemmeden Basin during the late Cretaceous and the early Tertiary. 


  Article infos

Published in Vol. 05, Fasc. 5 (1972)

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Batoids (Rajiformes, Torpediniformes, Myliobatiformes) from the Sülstorf Beds (Chattian, Late Oligocene) of Mecklenburg, northeastern Germany: a revision and description of three new species
Thomas Reinecke
Keywords: Batoids; Chattian; Elasmobranchii; North Sea Basin; Oligocene

doi: 10.18563/pv.39.2.e2
 
  Abstract

    Bulk-sampling of fossil-rich tempestites from the Chattian Sülstorf Beds of
    Mecklenburg, north-eastern Germany, yielded a rich selachian fauna in which batoids
    predominate by the abundance of teeth but are subordinate by the number of taxa. Thirteen
    taxa are identified, among which rajiform batoids are the most diverse (six species). One
    genus and three species are newly described: Raja thiedei sp. nov., Oligoraja pristina gen. et
    sp. nov., and Torpedo chattica sp. nov. Two species are reallocated: Atlantoraja cecilae
    (Steurbaut & Herman, 1978) new comb., and Dipturus casieri (Steurbaut & Herman, 1978)
    new comb. Ontogenetic heterodonty is documented for the first time in the dental pattern of
    Myliobatis sp. Stratigraphical ranges of batoid taxa in the period from Rupelian to Langhian
    are presented and partly discussed in context with the palaeoclimatic evolution and
    palaeogeographic situation of the North Sea Basin. 


  Article infos

Published in Vol.39-2 (2015)

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Le genre Plagiolophus (Palaeotheriidae, Perissodactyla, Mammalia): révision systématique, morphologie et histologie dentaires, anatomie crânienne, essai d'interprétation fonctionnelle
Jean-Albert Remy
Keywords: New taxa; Paléogène; perissodactyls; skull anatomy; tooth histology
 
  Abstract

    The genus Plagiolophus is documented, almost solely in Western Europe, from the middle Eocene up to the mid Oligocene (MP 12 to MP 25), i.e. more than for 15 MY. Seventeen species are now recorded whose two of them are new, P. ringeadei nov. sp. and P. mamertensis nov. sp. Some anatomical variations and the deflection of certain evolutionary trends justify the distinction of three subgenera, Paloplotherium, Fraasiolophus nov. and Plagiolophus s.s. The genus displays a wide range in size and weight (between 10 and 150 kg). The detailed description of the skull of several species is here given for the first time.
    Despite important evolutionary drifts during this long time span, the dentition shows a great structural homogeneity, which renders difficult the determination of fragmentary specimens or isolated teeth. It is characterized by a great heterodonty; premolars are little molarized and present a certain regression through time with paradoxically some progress in the molarization. The hypsodonty increases: the first Plagiolophus are hardly less brachyodont than Propalaeotherium, and the last ones are nearly as hypsodont as Merychippus from the early Miocene. The upper molars change from a wide crown pattern, with an open occlusal surface, lightly oblique transverse lophs and rounded internal cusps, to a narrower pattern, with a frontally constricted occlusal surface and internal lophs aligned parallel to the ectoloph. The M3/3 become always longer.

    The dental enamel displays horizontal Schreger-bands with imprecise limits occupying only the middle part of the enamel layer. The dentine is remarkable by its high rate of pericanalicular dentine. The crown cementum, lacking in earlier forms, increases to the point where it fills the occlusal valleys of the
    teeth.

    The masticatory musculature shows a increasing prominence of the temporal, with probably an important role devoted to the pterygoid muscles in lateral movements related to a two-phase type of chewing.

    The evolution of the dentition, of the masticatory musculature and of the repartition of masticatory forces indicate that the Plagiolophus have known different diets through their long evolutionary history; at first browsers they became mixed feeders and finally grazers. Their relatively long neck allowed these animals to reach different vegetal layers. The strength of the nuchal crests also suggests that they were able to have strong backwards movements of the head to pull up their food.

    This evolution of diet seems related to the slow degradation of environmental conditions attested during this period in western Europe, with the generalization of more open landscapes, increasing aridity and more marked seasons.

    Besides, a remodeling of the face is ontogenetically and along time observed, in relation with the evolution of the masticatory apparatus and especially with that of the mandibular lever arm. The postcanine diastemata become longer in the course of evolution; the free extremities of the nasals are always relatively long which contradicts the hypothesis according to which Paloplotherium may have had a trunk. At last the lineage Fraasiolophus can be distinguished by the presence of a deep malar fossa, probably related to a strong development of the maxillo-labialis superior muscle.

    The orbit is always large and tends to increase in size, which indicates a good development of the vision and its increasing role in the life relations. A peculiar type of epitympanic sinus could have been used as a resonance chamber insuring a certain amplification of sounds before their transmission to the eardrum. The endocranial cast reveals a relatively large brain with an advanced degree of gyrencephaly. Beside the role eventually played in food research and social relations, these neurophysiological abilities, also related to an advance in cursorial fitness, could have contributed to the survival of these animals facing the predation pressure of the first fissipede carnivores and the competition with new immigrant herbivores after the "Grande Coupure".
    On the basis of some shared apomorphies with the Pachynolophinae, which prevent from considering the latter as Equidae (molarization of the premolars, reduction of the premaxilla dorsal apophysis, peculiar epitympanic sinus, splitting of the jugular process), the hypothesis of an autochthonous origin of Plagiolophus issued from a form near Propalaeotherium, is once again proposed and discussed. Finally, intra-generic relationships are taken into consideration. 


  Article infos

Published in Vol. 33, Fasc. 1-4 (2004)

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The new Algerian locality of Bir el Ater 3: validity of Libycosaurus algeriensis (Mammalia, Hippopotamoidea) and the age of the Nementcha Formation
Fabrice Lihoreau, Lionel Hautier and Mahammed Mahboubi
Keywords: Dispersal event; Miocene; North Africa; Tetralophodon

doi: 10.18563/pv.39.2.e1
 
  Abstract

    The description of original material of anthracothere and proboscidean in the new locality of Bir el Ater 3 from East Algeria, and a thorough review of early Libycosaurus remains of Bir el Ater 2 allows us validating L. algeriensis as the smallest and earliest species of Libycosaurus and probably the earliest migrant of the genus from Asia. The presence of a Tetralophodon in the Neogene Nementcha formation might represent the earliest occurrence of the genus in Africa. These original fossil remains allow us to discuss the age of the Neogene part of the Nementcha formation close to the Serravalian/Tortonian boundary. 


  Article infos

Published in Vol.39-2 (2015)

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Critical comments on the genus Propachynolophus Lemoine, 1891 (Mammalia, Perissodactyla, Equoidea)
 
Jean-Albert Remy
Keywords: Eocene; Eurohippus; Pachynolophus; Propalaeotherium; tooth morphology

doi: 10.18563/pv.41.1.e3
 
  Abstract

    Abstract
     The validity of Propachynolophus Lemoine, 1891, supposedly an intermediate between Hyracotherium Owen, 1841 and Pachynolophus Pomel, 1847, has been questioned for a long time. A detailed analysis of features on which this genus is based further supported by a formal cladistic analysis demonstrates that Propachynolophus is not a valid taxon. The type species, “Propachynolophus gaudryi Lemoine, 1891” shall be assigned to Propalaeotherium Gervais, 1849, under the new combination Propalaeotherium gaudryi (Lemoine, 1891). “Pachynolophus maldani Lemoine, 1878”, later assigned to Propachynolophus, typifies the new genus Orolophus, under the binomen Orolophus maldani (Lemoine, 1878). The other referred species, “Propachynolophus levei Hooker, 1994” and “P. remyi Checa-Soler, 1997” are poorly documented, and both species shall be provisionally referred to as “Hyracotherium levei (Hooker, 1994) and “Hyracotherium remyi (Checa-Soler, 1997), pending new discoveries.
     
      


  Article infos

Published in Vol 41-1 (2018)

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