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The Ctenodactylidae (Rodentia) from the Oligocene of Ulantatal (inner Mongolia, China)
Monique Vianey-Liaud, Norbert Schmidt-Kittler and Laurent Marivaux
Published online: 12/15/06

Keywords: Adaptive radiation; Ctenodactylidae; Mongolia; Oligocene; Rodents

  Abstract

    This paper proposes a systematic revision of the Oligocene Mongolian Ctenodactylidae, on the basis of abundant material obtained by screen/washing operations in stratified localities of the Ulantatal area (Inner Mongolia) (UTL1, 2, 3, 4, 5, 7, 6 & 8). A Chinese-German team has collected several thousands of isolated rodent teeth, and a number of fragmentary jaws. A new genus is identified (Alashania nov. gen. tengkoliensis nov. sp.), and eight former species are reevaluated, Karakoromys decessus, Tataromys sigmodon, T. minor, T. plicidens, Yindirtemys ulantatalensis, Y. bohlini, Y. deflexus, with several synonymies. A new Yindirtemys species is described: Y. shevyrevae nov. sp. and another one close to that: Y. aff. shevyrevae nov. sp. Four new species, which are rare in the localities, remain in open nomenclature because they are not well-represented. Yindirtemys differs from the other genera by the permanence of crescentic structures, while the other genera show a general reduction of the trigonoid area (= anterior valley). We define a range of size variation for each well documented population. Although the dental morphology shows a wide range of variation, given that transitional morphologies occur in a single locality, it is possible to provide a clear definition for most species. We show that dental patterns of the different genera can be derived from the pattern of Karakoromys. As a number of Tataromyinae have been determined in several localities from China, Kazakhstan and Mongolia, usually on the basis of scarce material, or surface collections, the present study would be used to re-evaluate their attribution inasmuch as the taxa are now placed in the Oligocene stratigraphy. The diversity of sizes and forms reflects the adaptive radiation of the family during the Oligocene, within a forested environment where the vegetation was probably abundant. 


  PV article infos

Published in Vol. 34, Fasc. 3-4 (2006)

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Les Paramyidae (Rodentia) de l'Eocène inférieur du bassin de Paris.
Jacques Michaux
Published online: 7/15/68

Keywords: Ailuraviinae; Eocene; Paramyinae; Rodents

https://doi.org/10.18563/pv.1.4.135-193

  Abstract

    The exploitation of new early Eocene localities in the Paris Basin has resulted in the collecting of  numerous mammalian remains, among which are about 300 isolated teeth representing the rodents. They belong, for the most part, to the paramyid group. Only the latest level of the early Eocene has yielded rodents belonging to the pseudosciurid group. The paramyids, the object of this study, are represented by at least 5 genera and 10 species; they are distributed among 4 clearly dilferentiated subfamilies : Paramyinae Simpson 1945, Pseudoparamyinae Michaux 1964, Ailuraviínae n. subf., Microparamyinae Wood1962.
    It results from this study that the principal types of rodents in the middle and late Eocene of Europe are clearly related to the forms described here: Plesiarctomys Bravard 1850 is related to Pseudoparamys Michaux 1964, Ailuravus Rütimeyer1891 to Meldimys n. gen., Gliravus hammeli Thaler 1966 to Microparamys nanus (Theilard1927), and some Masillamys Tobien 1954 to Microparamys russelli Michaux 1964 and to M. sp. 1. Gliravus and Masillamys are the oldest representatives of the Gliridae and the Pseudosciurídae, respectively, families which will progressively replace the Paramyidae in the course of the middle and late Eocene.
    Two stages can be recognized in the history of te European Paramyidae fauna during the course of the early Eocene: the older is characterized by the Mutigny fauna, the younger by the Cuis fauna.
    The Mutigny fauna appears already rather diversified and does not completely correspond, point by point, to the homologous fauna of North America. A geographic differentiation seems to have been manifested rapidly, unless the fauna established in Europe was already a little different from that which established itself in North America. 


  PV article infos

Published in Vol. 01, Fasc. 4 (1968)

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Les traces de pas d'amphibiens, de dinosaures et autres reptiles du Mesozoïque Français : inventaire et interprétations.
Georges Gand, Georges Demathieu and Christian Montenat
Published online: 12/15/07

Keywords: Footprints; France; Inventory; Mesozoic; palaeontology; palaeovenvironments; Stratigraphy

https://doi.org/10.18563/pv.35.1-4.1-149

  Abstract

    Since the 19th century, thousands of footprints were observed in the geological series of the French Mesozoic. All are located in the Triassic and Jurassic. After a promising beginning, in France, it is only a few papers which will be published in the first half 20th century, unlike the USA and of others countries of Western Europe. One ought to wait about 1950 for a revival and now they are nearly 200 papers which were devoted to the ichnofossils. The literature abundance and the renewed interest of the naturalists for the palichnologic studies decided to us to write a synthesis work. This one begins with a stratigraphic inventory in which, localisation, age and paleontological contents of about 180 fossiliferous sites are specified. After having pointed out the followed methods, the footprints paleontological interpretation is then approached in detail and the results obtained are replaced in stratigraphy to deduce the fauna evolution during the Mesozoic. So, it appears that Ichnologic data, more varied and rich in the Triassic and Liassic than those relating to the bones, very rare for the considered periods, are very informative. The middle Triassic (Anisian-Ladinian), thus reveals Cotylosauria, Lepidosauria, Crurotarsi with Rauisuchia, Ornithosuchidae, Crocodylia and Dinosauromorpha more the "Prodinosauria": Dinosamiforme whose skeletons are known in Argentina but only in Ladinian. The rather fast domination of Dinosaurs during Norian is also as well shown. The almost exclusive presence of their footprints, up to fifty cm long, in the Lower Hettangian indicates their supremacy in the environments. Footprints characterise not very deep life places located between inter-supratidal limits and often out of water. Sedimentologic and Palaeontologic studies showed that they were great coastal spaces during Middle Triassic, flood-plain with sebkhas while Upper Triassic, and a large !!coastal marsh!! in Grands-Causses during Liassic in which, mainly, fine stromatolithic layers were deposited. During the same periad, bay beaches spread in Vendée. During the Middle Jurassic, they are also brackish to lacustrine environments and recifallagoons in- the Upper Jurassic. Numerous measurements of the footprints and trackways directions showed that the animaIs moved there in weil defined directions, for long periods. They seem due to the palaeotopography of the life environments relatively stable. Also, the discovery of vegetal radicular networks and small footprints far away from the continental borderlands has suggested that the animals continuously lived in these palaeoenvironnements, belonging to large ecosystems, where the sedimentation rate was weak. This explains that thebadies could not fossilize there but only their footprints through the cyanobacterian action in main cases. From the vertical distribution of different ichnospecies, defined with adapted statistical methods, explained in this work, a palichnostratigraphy was established for the Middle Triassic. Although the footprints are also abundant in Hettango-Sinemurian of "Grands-Causses" and the Vendée, it was not possible, up to now, to establish any zonation in this series; Probably because the palichnofauna is too little diversified there, currently reduced to a majority of Theropods II-IV tridactyl traces.
      


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Published in Vol. 35, Fasc. 1-4 (2007)

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Révision systématique des Anchilophini (Palaeotheriidae, Perissodactyla, Mammalia).
Jean-Albert Remy
Published online: 10/15/12

Keywords: Anchilophus; Eocene; new genus; new species; Palaeotheriidae; Paranchilophus; Perissodactyla; Systematics

https://doi.org/10.18563/pv.37.1-3.1-165

  Abstract

    The knowledge of the Anchilophini has been lately renewed by the discovery of a rather large amount of new material still largely unpublished. This new material offers the opportunity of a systematic revision of this tribe gathering those of European Eocene Equoidea which bear no mesostyle on upper check teeth and display a heavy trend to the molarization of premolars.

    A cladistic analysis has made out two genera, Anchilophus (Paranchilophus included as a subgenus), characterized by a marked lophodonty and the transverse narrowness of the cheek teeth, a rather high hypsodonty, the frequent occurrence of "crochets" and "anticrochets" on the superior ones, and a rather weak molarization of the premolars, opposite to Metanchilophus n. gen. whose cheek teeth are more transversally elongated, less high, less lophodont, with cusps better distinct, enamel thicker and premolars more molarized on the whole.

    Three species of Anchilophus are recognized, A. desmaresti, type species of the genus, A. (Paranchilophus) remyi and A. (Paranchilophus) jeanteli n. sp.

    The genus Metanchilophus is more diversified with the species dumasi, radegondensis, gaudini (whose a new sub-species M. g. fontensis is defined), depereli, castrensis n. sp. and chaubeti n. sp.

    The skull anatomy has been moreover described with several taxa; it brings to light (for all that one can generalize) that Anchilophini were light animals with a slender and elongated snout, a thin zygomatic arch, a rather developed encephalon with an advanced gyrencephaly.

    The structure of the nasal opening together with the occurrence of epitympanic sinuses and the molarizing process of the premolars corroborate the attribution of this tribe to the family PalaeotheIiidae. 


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Published in Vol. 37, Fasc. 1-3 (2012)

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Old world hemiones and new world slender species (Mammalia, Equidae)
Véra Eisenmann, John Howe and Mario Pichardo
Published online: 12/16/08

Keywords: Amerhippus; biometry; Equus; Holocene; New World; Old World; Osteology; Pleistocene; Pliocene

https://doi.org/10.18563/pv.36.1-4.159-233

  Abstract

    Morphological and biometrical description of skulls, teeth, and limb bones of extant and fossil Old World herniones (including E. hydruntinus) and of New World 'stilt-Iegged' and other slender species from Blancan to Holocene. An Appendix presents ways in which the approximate size of some missing bones or dimensions may be deduced from available ones.

    The discussed and/or illustrated fossils were found in Bolivia (Tarija), Canada (Yukon), China (Choukoutien, Gulongshan, Jiling, Loufangzi), Ecuador (Oil Fields), Ethiopia (Melka Kunturé), France (Lunel-Viel), Germany (Süssenborn), Greece (Agios Georgios, Petralona), Hungary (Dorog), Italy (Romanelli), Mexico (Cedazo, San Josecito), Mongolia (Sjara-osso-gol), Spain (Venta Micena), ex-Soviet Union (Akhalkalaki, Binagady, Chokurcha, Chukochya, Kabazi, Kolyma, Krestovka, Kurtak, Staroselie, Tologoj), USA (Alaska, Arkalon, Cedar Meadow, Channing, Conkling, Dry Mountains, Hay Springs, Leisey Shell Pit A, Lissie Formation, Natural Trap, Pool Branch, Powers Ranch, Rock Creek, San Diego, Santo Domingo, Seymour Formation, Shelter, Slaton, Trinity River). Numerous raw or statistically elaborated data are given in Tables.

    There is no evidence for the existence of Old World hemiones in the New World nor of 'stilt-Iegged' equids in the Old World. The first 'stilt-Iegged' equid was found at Santo Domingo, New Mexico, and is believed to be Late Blancan. It was probably at the origin of E. calobatus (Arkalon, Rock Creek) and of the smaller E. semiplicatus (Channing, Rock Creek). Slender, but not 'stilt-Iegged', equids found at Natural Trap, Wyoming, ca. 12 ky ago belong to Amerhippus. AlI these species share with Oid World Sussemiones (and some hemiones) peculiar patterns on the lower cheek teeth.

    The slender Equus sp. B of Leisey Pit A, Florida, ca. 1.2 Ma, as weIl as Amerhippus francisci and E. tau (probably a senior synonym of E. quinni) share conventional lower cheek teeth patterns. The skulls of A. francisci and E. tau, however, are quite different.

    Paleontological data suggest a common origin of Amerhippus, Sussemiones, and 'stilt-Iegged' equids during the late Blancan. Old World hemiones seem to have differentiated later. 


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Published in Vol. 36, Fasc. 1-4 (2008)

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Première occurrence d'un mégachiroptère ptéropodidé dans le Miocène moyen d'Europe (Gisement de Lo Fournas-II, Pyrénées-Orientales, France).
Jean-Pierre Aguilar, Marc Calvet, Jean-Yves Crochet, Serge Legendre, Jacques Michaux and Bernard Sigé
Published online: 10/31/86

Keywords: Europe; First occurence; Megachiroptera; Middle Miocene; Teeth

  Abstract

    A lot of isolated teeth of a pteropodid fruit bat has been recently found within an assemblage of micromammals recovered from a karstic fissure filling named Lo Fournas-Il near the locality of Baixas (Pyrénées-Orientales, France). The fauna is Middle Miocene Serravallian age. The fossil fruit bat appears morphologically close to Rousettus; its size is that of a recent medium-sized fruit bat. While the fruit bats are very poorly known as fossils, this discovery shows that one of their recent types of dentitions was perfectly established by Middle Miocene times, and supports the presumed long geologic story of the suborder. One of the major invasions of the Old World fruit bats, supposed originated from SE Asia, reached up to Europe. A suborder unit is added to the miocene fauna of this continent. 


  PV article infos

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

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L'occlusion dentaire chez Peradectes, Amphiperatherium et Peratherium, Marsupiaux du tertiaire d'Europe.
Jean-Yves Crochet
Published online: 10/1/80

Keywords: Didelphidae; Eocene; Mastication; Oligocene; Wear facets

  Abstract

    The general principles guiding the study of wear facets which develop during mastication in mammals possessing tribosphenic molars are named. The application of this method of study to the molars of European Tertiary Didelphidae shows that the lineage of this family as represented by the species Peratherium cuvieri (Upper Eocene), P. elegans (Lower-middle Oligocene) and P. antiquum (Upper Oligocene) has propessively evolved toward a more carnivorous diet. 


  PV article infos

Published in Vol. 9, Ext (1980)

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Prospection paléontologique de la région de Torralba de Ribota (Burdigalien du bassin de Calatayud, prov. de Zaragoza, Espagne)
Edouard Boné, Maria T. Alberdi, Manuel Hoyos and Nieves Lopez-Martinez
Published online: 10/1/80

Keywords: Faunal assemblage; Macromammals; Spain; Zaragoza prov.

  Abstract

    The study of another faunal assemblage (mostly macromammals) from Torralba de Ribota (Calatayud, Zara-
    goza Prov.) demonstrates the Middle "Burdigalian" age of the deposit, MEIN zone 4a. Some ten genera have been recognized. a.o. Anchitherium, Aceratherium and Lagopsis


  PV article infos

Published in Vol. 9, Ext (1980)

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Les Palaeotheridae (Perissodactyla) de la faune de Mammifères de Fons 1 (Eocène supérieur).
Jean-Albert Remy
Published online: 6/15/67

Keywords: Anchilophus; Eocene; Pachynolophus; Palaeotheriidae; Perissodactyla

https://doi.org/10.18563/pv.1.1.1-46

  Abstract

    The locality of Fons 1, one of the fossiliferous outcrops in the late Eocene limestones of Fons-outre-Gardon (Gard), has yielded varied remains of mammals. The specimens were prepared by dilute acetic acid attack on the rock and by impregnation with an acrylic resin.
    This fauna, rich with about 20 species, can be included in the biochronologic zone of Euzet. The Palaeotheridae (sensu Simpson 1945), represented by 6 species, occupy a predominant place; Plagiolophus annectens is particularly abundant, comprising 55% of all the specimens found.
    The abundance of this species has permitted a detailed comparative study with the corresponding form from Euzet. The quantitative tests brought out a slight but highly sígnificant difference between the average dimensions of the teeth in the two populations. Moreover and in spite of the feeble rate of evolution in the Plagialophus dentition, diverse archaic particularities can be seen which permit the conclusion that the form from Fons 1 is a little the older. This conclusion is corroborated by observations on the other palaeotherids, particularly Lophiotherium aff. cervulum, whose dental evolutionary stage is intermediate between those of the corresponding forms known from Robiac and Euzet.
    A new species of Pachynolophus is described, P. garimondi n.sp., the last representative known of the genus. lts teeth are distinguished by their size, a great heterodonty, and the weakness
    of their cingula. 


  PV article infos

Published in Vol. 01, Fasc. 1 (1967)

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Les Chiroptères du Miocène inférieur de Bouzigues. 1- Etude systématique.
Bernard Sigé
Published online: 4/17/68

Keywords: bats

https://doi.org/10.18563/pv.1.3.65-133

  Abstract

    In recent years, the techniques of chemical preparing have permitted a rich paleontologic material to be obtained from the phosporitic sediment of Bouzigues (Hérault, France). The fauna of this locality is comprised of quite varied microvertebrates, amphibians, reptiles, birds, mammals. Twenty five species of the latter, belonging to seven orders, are today known from the site. Among them, the numerous rodents have allowed L. Thaler to chronologically situate this fauna in the Zone of Laugnac (<< late Aquitanian ›> of some authors).
    The chiropterans are, with the rodents, the best represented of the locality's mammals. Three families comprise the bat fauna, with nearly complete dominance by one of them (Hippoxideridae) over the two others (Megadermatidae and Vespertílionidae)
    Six forms are described, of which three are new species and one a new sub-genus.
    Megaderma braillomi n. sp., an animal of rather large size, shows like the Miocene megaderms several evolved dental characters, translating the adaptation of these animals to a partially carnivorous regime. The Bouzigues species seems, however, to represent a particular lineage.
    Hipposideros (Brachipposideros n. subgen.) dechaseauxi n. sp. and Hípposideros (Brachipposideros) cf. collongenris Depéret, small sized forms, belong to a group rather well represented in the late Oligocene and early Miocene of Europe, and not distinguished until now within the genus Hipposideros.
    Hipposideros (Pseudorhinolophus) bouziguensis n. sp., is the most abundant mammal in the locality and, occuring at the Oligocene-Miocene limit, the last representative known of the subgenus Pseudorhínolophus, common in Europe from the middle Eocene.
    However, beyond Neogene and Quaternary times, certain among the numerous living species of Hipposideros are close to Pseudorhinolophus and others to Brachipposíderos. 'This fact would in the future justify a global revision of the genus, on the basis of comparative anatomy of the squeleton and of the teeth.
    The bat fauna of Bouzigues is completed by two small Vespertilionidae, rare forms, Myoris sp. I and sp. II.
      


  PV article infos

Published in Vol. 01, Fasc. 3 (1968)

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Les rongeurs de l'Eocène d'Afrique Nord-Occidentale [Glib Zegdou ( Algérie) et Chambi (Tunisie)] et l'origine des anomaluridae.
Monique Vianey-Liaud, Jean-Jacques Jaeger, Jean-Louis Hartenberger and Mahammed Mahboubi
Published online: 5/20/94

Keywords: Africa; Eocene; New taxa; Paleobiogeography; PHYLOGENY; Rodents

  Abstract

    This paper is about the oldest African rodents faunas, from the late Early Eocene, or early Middle Eocene, Glib Zegdou (Algeria) and Chambi (Tunisia) localities. Five species are described and figured, belonging to a new family here created, the Zegdoumyidae.

    This family is compared to the Early and Middle Eocene rodents families from Asia, Europe and North America (Chapattimyidae, Yuomyidae, Gliridae, Theridomyidae, lschyromyidae and Sciuravidae), as well as to those known from the Late Eocene African locality Bir El Ater (Anomaluridae and Phiomyidae).

    On the one hand, it seems clear that the African endemic Anomaluridae arise from the Zegdoumyidae. On the other hand, the lschyromyidae, or primitive Sciuravidae, may be the most reliable ancestral groups for the Zegdoumyidae. Thus, this new family can be considered as the sister group for the American Sciuravidae on the one hand, and for the European Gliridae on the other hand.

    The biogeographical consequences of these phylogenetic hypotheses are discussed. A new phase of communication between Europe and North Africa is inferred, during the Early Eocene. It has been followed by a short period of endemism, allowing the adaptive radiation for the Zegdoumyidae, preceding the immigration of the Phiomyidae, during the Late Eocene, probably from Asian relatives. 


  PV article infos

Published in Vol. 23, Fasc. 1-4 (1994)

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The lower Miocene artiodactyls of Tagai bay, Olhon island, lake Baikal (Russia)
Inesa Vislobokova
Published online: 5/20/94

Keywords: Artiodactyls; Mammals; Miocene; Siberia

  Abstract

    The mammalian fauna of the Tagai locality of Olhon Island in Lake Baikal contains six artiodactyls:
    Amphitragulus boulangeri, Lagomeryx parvulus, Stephanocemas sp., Palaeomeryx kaupi, Orygotherium aff. escheri, and Brachyodus intermedius. They are reported from Eastern Siberia for the first time. A description of teeth and limb-bones are given. An analysis of the systematic composition of the Tagai fauna allows it to be correlated with European faunas of the second part of the Early Miocene (Orleanian, MN 3-4) and permit suggestion of the existance of a united European-Siberian zoogeographical sub-area in the middle latitudes of Eurasia at that time. 


  PV article infos

Published in Vol. 23, Fasc. 1-4 (1994)

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Octodontid-like Echimyidae (Rodentia) : an upper Miocene episode in the radiation of the family
Diego H. Verzi, Maria G. Vucetich and Claudia I. Montalvo
Published online: 5/20/94

Keywords: Argentina; Echimyidae; Miocene; New taxa; Rodentia; South America

  Abstract

    Reigechimys octodontiformis gen. et sp. novo and R. plesiodon sp. novo are described. They represent the frrst record of the family Echimyidae for the Cerro Azul Formation (Huayquerian Age, Late Upper Miocene) at La Pampa Province, central Argentina. Both species have hypsodont cheek teeth with an eight-shaped occlusal design. This dental morphology represents a noticeable case of convergence to octodontids and indicates that these echimyids inhabited open environments. 


  PV article infos

Published in Vol. 23, Fasc. 1-4 (1994)

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Rongeurs nouveaux de l'Oligocène Moyen d'Espagne.
Louis Thaler
Published online: 9/15/69

Keywords: Cricetidae; Oligocene; Pseudocricetodon; Rodents; Theridomys

https://doi.org/10.18563/pv.2.5.191-207

  Abstract

    Description of four new rodents from a recently discovered locality at Montalban. Theridomys crusafonti nov. sp. is considered as the ancestry of T. Iembronicus. Theridomys varian: nov. sp. includes «Theridomys» morphotypes and «Blainvilllimys» morphotypes; it could be ancestral to B. blainvillei. Pseudoltinomys nanus nov. sp. represents a new lineage paralleling in evolution that of P. gaillardi (which is equally found at Montalban). Pseudocricetodon montalbanensis nov. gen., nov. sp. designates a lineage of very small Cricetidae accompanying Eucricetodon. With these well defined new species and six others present in the locality, Montalban appears as the best faunal reference point within the biochronologic zone of La Sauvetat.
    As an annex, discussion of two rodent specimens from the classic localíty of Tárrega, close in age to that of Montalban. 


  PV article infos

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

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Palaeotis weigelti restudied : a small middle Eocene Ostrich (Aves : Struthioniformes)
Peter Houde and Hartmut Haubold
Published online: 6/20/87

Keywords: Aves; Central Europe; Middle Eocene; Palaeotis; Struthioniformes

  Abstract

    Palaeotis weigelti, from the Middle Eocene of central Europe, is a flightless, paleognathous bird. It appears to be a member of the ostrich lineage on the basis of trivial derived characters. It is a very primitive ratite, however, and does not possess any of the highly specialized cursorial adaptations that characterize the modern steppe -and savanna- dwelling ostriches. 


  PV article infos

Published in Vol. 17, Fasc. 2 (1987)

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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
Published online: 12/15/04

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. 


  PV article infos

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

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Two new scyliorhinid shark species (Elasmobranchii, Carcharhiniformes, Scyliorhinidae), from the Sülstorf Beds (Chattian, Late Oligocene) of the southeastern North Sea Basin, northern Germany.
Thomas Reinecke
Published online: 4/30/14

Keywords: Chattian; Elasmobranchii; North Sea Basin; Scyliorhinidae; Scyliorhinus

https://doi.org/10.18563/pv.38.1.e1

  Abstract

    Based on isolated teeth two new scyliorhinid shark species, Scyliorhinus biformis nov. sp. and Scyliorhinus suelstorfensis nov. sp., are described from the Sülstorf Beds, early-middle Chattian, of Mecklenburg, northeastern Germany. They form part of a speciose assemblage of necto-benthic sharks and batoids which populated the warm-temperate to subtropical upper shelf sea of the south-eastern North Sea Basin. 


  PV article infos

Published in Vol.38-1 (2014)

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A new and primitive species of Protophiomys (Rodentia, Hystricognathi) from the late middle Eocene of Djebel el Kébar, Central Tunisia
Laurent Marivaux, El M. Essid, Wissem Marzougui, Hayet Khayati Ammar, Sylvain Adnet, Bernard Marandat, Gilles Merzeraud, Rodolphe Tabuce and Monique Vianey-Liaud
Published online: 6/2/14

Keywords: Adaptive radiation; Bartonian; Dental morphology; North Africa; Paleobiogeography

https://doi.org/10.18563/pv.38.1.e2

  Abstract

    Based on fossil discoveries and phylogenetic studies, an Eocene Asian origin for hystricognathous rodents and anthropoid primates has gained strong support in recent years. The two groups then invaded both Africa and South America, which promoted their evolutionary success. However, the fossil record has so far failed to constrain the nature and precise timing of these pivotal dispersal events. In Africa, given the apparent absence of hystricognaths and anthropoids in early to early middle Eocene localities, it is suggested that these mammal groups dispersed from Asia to Africa sometime during the middle Eocene. In this paper, we report the discovery of several isolated teeth of a rodent from a new vertebrate locality situated in central Tunisia (Djebel el Kébar, KEB-1), dating from the late middle Eocene (Bartonian, ~39.5 Myr). These fossils document a diminutive new species of Protophiomys (P. tunisiensis nov. sp.), a basal genus of hystricognathous rodents which is well known from several North African mammalian-bearing localities of the end of the Eocene. The teeth of P. tunisiensis display a suite of anatomical details comparable with those observed in the other species of the genus, but with a lesser degree of development. Such an apparent primitive evolutionary stage is corroborated by the greater antiquity of this Tunisian species. P. tunisiensis nov. sp. is so far the most ancient representative of hystricognaths in Africa. However, it can be expected that hystricognaths were already present on that landmass given the new data on early caviomorphs recently reported from South America (at ~41 Myr). The arrival of hystricognaths in Africa from South Asia certainly predates the depositional period of the Kébar sediments, but perhaps not by much time. 


  PV article infos

Published in Vol.38-1 (2014)

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Rodent paleocommunities from the Oligocene of Ulantatal (Inner Mongolia, China)
Helder Gomes Rodrigues, Laurent Marivaux and Monique Vianey-Liaud
Published online: 6/10/14

Keywords: late Paleogene; Mammalia; Mongolian Plateau; Rodentia; Systematics

https://doi.org/10.18563/pv.38.1.e3

  Abstract

    The Oligocene deposits of the Ulantatal area in Inner Mongolia (China) contain among the richest mammalian faunas from Asia. To date, only some parts of the rodent faunas have been described. Here, we propose to review the rodent faunal lists for each site, including the description of a few new rodent specimens. We describe three additional rodent species: the Cylindrodontidae Anomoemys lohiculus, the Eomyidae Asianeomys sp., and the Dipodidae Litodonomys huangheensis. This study allows us to constrain the stratigraphic range of Anomoemys lohiculus, which ranged from the late Early Oligocene to the early Late Oligocene in this area. Asianeomys sp. and Litodonomys huangheensis are dated from the latest Oligocene. These Oligocene deposits consist now of more than 70 species of mammals if we include the fauna from Kekeamu. This latter corresponds to the basal part of the Ulantatal Formation and could be dated biochronologically from the earliest Oligocene. When compared to the faunas from the Valley of Lakes in Central Mongolia, the Ulantatal faunas present a great majority of rodents, and this difference can be partly explained by sampling and description biases regarding macro-mammals. This study also shows that variations existed between Inner and Central Mongolia, especially regarding the composition of the rodent paleocommunities. However, the assessment of their evolutionary history in this part of Asia with respect to the important climate and environment changes, require further precisions and more material than current data allow. 


  PV article infos

Published in Vol.38-1 (2014)

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The stratigraphic sequence of North American rodent faunas
Robert W. Wilson
Published online: 10/1/80

Keywords: North America; Rodents; Stratigraphic sequence

  Abstract

    Rodents first appear in the latest Paleocene or earliest Eocene as very fragmentary specimens (Family Paramyidae) known largely from a single locality. After this sparse beginning, rodents are usually abundant in the North American record if proper recovery methods are used. Utilization of rodents for biostratigraphic purposes depends on 1/ extinction, and 2/ replacement by evolution of endemic groups and/or incursions of Old World rodents, and rarely and late by South American kinds. These incursions are separated by relatively long periods of isolation in the Paleogene, but more episodic in the Neogene. At least 10 rodent zones can be characterized by major distinctions, and these zones can be amplified into as many as 16 with little trouble. In general, rodent genera permit as refined a zonation as do genera of large mammals. Distinction at a specific level has not been attempted herein except in the Blancan and Post-Blancan. 


  PV article infos

Published in Vol. 9, Ext (1980)

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