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Page 12 of 19, showing 20 record(s) out of 365 total

Les Otolithes de téléostéens du Miocène de Montpeyroux (Herault),France).
Dirk Nolf and Henri Cappetta Logo
Published online: 15/12/1980

Keywords: Miocene; Montpeyroux; Otolithes; teleostean fish

https://doi.org/10.18563/pv.10.1.1-28

  Abstract

    Sieving and washing of about 700 kg of sediment from the miocene site at Montpeyroux produced otoliths of 34 teleost species, of which four still occur in the present day fauna or are near to extant species. Among the fossil species, eight are new : Ilisha lerichei, «genus Clupeidarum ›› orbiculatus, Dipulus mediterraneus, Morone cornuta, Chanda nelsoni, Pomadasys steurbauti, «genus Sciaenidarum ›› barthassadensis and Paraplagusia roseni. The fauna found is typical for a tropical or subtropical very littoral, probably even estuarine environment; it was living in a period near the boundary between Lower and Middle Miocene, perhaps somewhat earlier. 


  PV article infos

Published in Vol. 10, Fasc. 1 (1980)

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Evolution of the Rhizomyine zygoma
Lawrence J. Flynn Logo, Mohammed Sarwar and Jean-Jacques Jaeger Logo
Published online: 30/12/1985

Keywords: parallel evolution; Rhizomyidae; Rodentia; Siwalik; zygoma

https://doi.org/10.18563/pv.15.3.129-138

  Abstract

    Cranial anatomy of a late Miocene rhizomyid, Brafhyrhizomys cf. B. pilgrimi, provides new evidence on the origin of the dorsal, round infraorbital foramen of living rhizomyines. Primitive rhizomyids retain a myomorphous keyhole foramen with a long ventral slit that retracts upward during the evolutionary history of the Rhizomyidae. The primitive condition of the elongated ventral slit is represented by Kanisamys sivalensis. Among later burrowers the foramen shows progressive dorsal migration, the ventral slit terminating midway up the snout in B.tertracharax and B. choristos ; well above the midline of the snout in Brachyrhizamys cf. B. pilgrimi. Apparently this transformation began earlier among Rhizomyinae than among Tachyoryctinae and continued to a more derived stage in rhizomyines. ln living Rhizomyx the ventral slit is absent and only a high round hole remains at the anterior end of the zygomatic arch. 


  PV article infos

Published in Vol. 15, Fasc. 3 (1985)

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Nouvelles faunes de rongeurs de la fin Miocène inférieur en Provence. Implications géologiques et Paléogéographiques.
Dominique Lalaï
Published online: 01/09/1986

Keywords: Biogeographic province; Biozonation; Correlation; Miocene; Palaeogeography; Rodentia

https://doi.org/10.18563/pv.16.2.77-126

  Abstract

    Rodents from the new localities of Châteauredon (Alpes-de-Haute-Provence) and La Denise (Bouches-du-Rhône) show more similarities with the rodents known from the Czecho-Slovak locality of Franzenbad than with the species found in contemporaneous Lower Miocene faunas located westward of the present Rhône Valley. This is another data wich support the existance of several biogeographical provinces in Southern France during Lower Miocene. The correlations which have been settled down allow new datations of several formations in Provence and give new information on the Aquitanian and Burdigalian paleogeographies of this region. More precise stratigraphical allocations are given to some other localities of Central Europe. 


  PV article infos

Published in Vol. 16, Fasc. 2 (1986)

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Les vertébres dévoniens de la Montagne Noire (Sud de la France) et leur apport à la phylogénie des pachyosteomorphes (Placodermes Arthrodires).
Hervé Lelièvre, Raimund Feist Logo, Daniel Goujet and Alain Blieck
Published online: 15/05/1987

Keywords: Devonian; Montagne Noire; New taxon; PHYLOGENY; Placoderms; Stratigraphy; Vertebrate

https://doi.org/10.18563/pv.17.1.1-26

  Abstract

    Several different taxa of jawed vertebrates are reported for the first time from the Devonian of south-eastern Montagne Noire, France. Besides some undeterminable fragments of placoderm fishes from the Pragian and Lower Emsian, the material from the Upper Devonian is mainly represented by Melanosteus occitanus gen. and sp. nov. (Frasnian) and Thoralodus cabrieri LEHMAN, 1952 ("Famennian"). The good state of preservation of Melanosteus allows a detailed anatomical study leading to a phylogenetic analysis of the selenosteid pachyosteomorphs. 


  PV article infos

Published in Vol. 17, Fasc. 1 (1987)

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Préface au mémoire jubilaire en hommage à René Lavocat
Jacques Michaux
Published online: 01/10/1980

Keywords: Editorial

https://doi.org/10.18563/pv.9.ext.1-13

  Abstract

    Monsieur René Lavocat, Directeur du Laboratoire de Paléontologie des Vertébrés de la troisième section de l'Ecole Pratique des Hautes Etudes, quittait le service actif en l'année 1979.
    Cela fait maintenant quinze ans que fut installé à Montpellier, le laboratoire de Paléontologie des Vertébrés de l'Ecole Pratique des Hautes Etudes. La décision de M. René Lavocat a été particulièrement heureuse dans ses conséquences. Il a en effet permis le développement de l'enseignement et de la recherche en Paléontologie des Vertébrés à l'Université de Montpellier où se créa un des centres importants de cette discipline, en France. Il suscita la création de nouveaux laboratoires de l'Ecole Pratique des Hautes Etudes installés dès leur origine à Montpellier, ainsi que le déplacement à Montpellier d'un Laboratoire de l'Ecole Pratique, préexistant. Ce groupe de laboratoires constitue maintenant l'Institut de Montpellier de l'Ecole Pratique des Hautes Etudes.
    [...] 


  View editorial

Published in Vol. 9, Ext (1980)

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Additions to the elasmobranch fauna from the upper Cretaceous of New Jersey (middle Maastrichtian, Navesink Formation)
Gerard R. Case and Henri Cappetta Logo
Published online: 15/12/2004

Keywords: Elasmobranchs; New Jersey; new species; Upper Cretaceous; USA

  Abstract

    A recently discovered, almost complete specimen of a hybodont tooth, allows us to describe as a new species, fairly common, but usually fragmentary teeth in the Navesink Formation of New Jersey: Hybodus novojerseyensis nov. sp.
    Three additional taxa are also described : Heterodontus creamridgensis, Squalicorax sp. and Pseudocorax affinis which is noted for the first time in North America.
    The whole elasmobranch fauna of the Early Maastrichtian localities of New Jersey is reevaluated and several generic assignments are changed in comparison to the list previously published in 1975 (Cappetta
    & Case). 


  PV article infos

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

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Découverte d'un gisement de micromammifères d'âge Pliocène dans le bassin de Constantine (Algérie), présence d'un muridé nouveau : Paraethomys Athmeniae n.sp.
Brigitte Coiffait and Philippe-Emmanuel Coiffait
Published online: 16/05/1981

Keywords: Algeria; Constantine; Micromammals; Muridae; Pliocene

https://doi.org/10.18563/pv.11.1.1-15

  Abstract

    The study of that locality allowed the description of a new Muridae : Paraethomys athmeniae n. sp. It reveals the existence of new rodent for Algeria : first, a Sciuridae, Atlantoxerus cf. rhodius, and second, a Gliridae, Eliomys truci. So, that work shows the presence of the genus Eliomys in North Africa before the middle of Pleistocene. Lastly, Paraethomys cf. anomalus gives an exact datation of that bed. 


  PV article infos

Published in Vol. 11, Fasc. 1 (1981)

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Contributions à l'étude des micromammifères du gisement Miocène supérieur de Montredon (Hérault). 2- Les rongeurs
Jean-Pierre Aguilar
Published online: 30/06/1982

Keywords: Hérault; Late Miocene; Micromammals; Montredon; Rodents

https://doi.org/10.18563/pv.12.3.81-117

  Abstract

    The recent excavation of the Upper Miocene locality of Montredon (Hérault) provides a rich material of Mammals. The present study deals with rodents. The new quarry is 10 meters above the classical Depéret's Quarry. No differences have been noticed between the rodent populations coming grom these two sites. The description of two new species : Hispanomys mediterraneus and Muscardinus heintzi is given and the dormouse Eliomys is recorded there for the first time. The new zonation of the Miocene given by Aguilar (1982) and the previously established correlations between marine and continental chronological scales give Tortonien age (estimated between 9 and 10 M.Y. old) to the site of Montredon, which belongs to the Mammal zone D 2. 


  PV article infos

Published in Vol. 12, Fasc. 3 (1982)

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Les Gruiformes (Aves) des phosphorites du Quercy (France). 1. sous-ordre cariamae (Cariamidae et Phorusrhacidae), systématique et biostratigraphie.
Cécile Mourer-Chauviré Logo
Published online: 30/11/1983

Keywords: Aves; Biostratigraphy; Birds; Cariamae; gruiformes; Quercy Phosphorites; Systematics

https://doi.org/10.18563/pv.13.4.83-143

  Abstract

    The revision of the old collections of fossil birds from the “Phosphorites du Quercy” and the study of new material give the following results (Gruiformes, Cariamae) :  The humeri and most of the carpometacarpi described under the name Filholornis belong in Elaphrocnemus. The ulnae ascribed to Fïlholornis belong in Idiornis. Most of the post-cranial elements of the genera Elaphrocnemus and Idiornis are described and show great similarities with recent Cariamidae and Opisthocomidae, and fossil Bathornithinae.  A new genus and a new species, Oblitavis insolitus, are created in the sub-family Idiornithinae; two new species are described in the genera Elaphrocnemus (E. brodkorbz) and Idiornis (I. itardiensis), and the species Elaphrocnemus gracilis is transferred to the genus Idiornis.  The genus Propelargus Lydekker is transferred from the family Ciconiidae to Cariamidae.  A new generic name, Occitaniavis, is created for the species Geranopsis elatus, which belong in Cariamidae, while the type-species of the genus, Geranopsis hastingsiae, is a member of the Gruidae.  The affinities between the Quercy avifauna and the Neotropical one is emphasized by the occurrence of Phorusrhacidae, previously known only from the Cenozoic of South America and the Late Pliocene or Early Pleistocene of North America. Thanks to the material collected during the new excavations, the stratigraphical position of most of the species is stated precisely, and evolutionary lineages are outlined. This study shows that the suborder Cariamae, presently restricted to two South American genera, was already extremely diversified during the Eocene, and widespread in Europe and North America. 


  PV article infos

Published in Vol. 13, Fasc. 4 (1983)

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The skull of Arsinoitherium (Mammalia, Embrithopoda) and the higher order interrelationships of ungulates
Nicholas Court
Published online: 17/12/1992

Keywords: Arsinoitherium; PHYLOGENY; Skull; Ungulate

https://doi.org/10.18563/pv.22.1.1-43

  Abstract

     Detailed anatomical description of arsinoithere cranial remains from the Lower Oligocene, Fayum Depression, Egypt, provides the basic data for a systematic investigation. All cranial and some postcranial features are assessed from a phylogenetic standpoint. Several soft tissue characters are then added to a cladistic analysis based on 54 derived ungulate morphological characters. The resulting phylogenetic hypothesis implies that perissodactyls, sirenians, proboscideans and arsinoitheres constitute a monophyletic unit (5 synapomorphies). However, increasing the tree length by 3 steps reveals a closer association between hyraxes and perissodactyls. Nevertheless, 13 synapomorphies link proboscideans, sirenians and  arsinoitheres to the exclusion of all other ungulates. Form of the sphenopalatine and ethmoid foramina, recurved posttympanic process, absence of a fenestra rotundum in the petrosal, vestigial paroccipital process of the exoccipital and the highly unusual absence of a hypoglossal foramen in the skull, imply a robust sister-group relationship between arsinoitheres and proboscideans. In this analysis artiodactyls share only one derived character with all other ungulates studied. Monophyly of Ungulata, including Artiodactyla, is therefore only weakly supported. It is argued that pedal anatomy of hyraxes is non-homologous with that of Tethytheria. Arsinoitherium should now be classified within Tethytheria, sharing a sister-group relationship with Proboscidea. Hyraxes are excluded, thus refuting the concept of Paenungulata. However, monophyly of the wider concept, Pantomesaxonia, containing hyraxes, perissodactyls, sirenians, proboscideans and now, arsinoitheres, is supported by this study. 


  PV article infos

Published in Vol. 22, Fasc. 1 (1992)

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Historical and new perspectives on the parataxonomyof fossil eggs.
Monique Vianey-Liaud Logo and Darla Zelenitsky Logo
Published online: 15/12/2003

Keywords: amniotic eggshells; Parataxonomy

  Abstract

    A critical review on the literature about the parataxonomy of amniote eggshells reasserts the great interest of this systematics tool for the progress of dinosaur eggshell paleontology. However, shedding light on its limits, we propose to give up the use of the basic types - morphotypes key system. 


  PV article infos

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

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Analysis of mammalian communities from the late Eocene and Oligocene of southern France
Serge Legendre Logo
Published online: 15/12/1986

Keywords: Late Eocene; Mammalian communities; Oligocene; Quercy; Southern France

https://doi.org/10.18563/pv.16.4.191-212

  Abstract

    Valverde's cenogram method is used to analyse mammalian communities from the late Eocene to late Oligocene of southern France, mainly from the "Phosphorites du Quercy". Cenogram analysis involves plotting the size of each component species in a fauna on a semilog diagram in rank order, permitting fossil faunas to be compared with Recent ones. The configurations of Recent communities serve as models for establishing the general environmental characteristics of fossil mammalian faunas. This method of analysis applied to faunal sequence can reveal major and sudden ecological perturbations. The paleobiogeographical event (i.e. the mammalian immigration wave) at the Eocene-Oligocene Boundary in western Europe, known as the «Grande Coupure", is here shown to represent a drastic and sudden ecological change: late Eocene tropical environments in Europe deteriorated rapidly turning to subdesert or desert environments al the beginning of the Oligoccne. 


  PV article infos

Published in Vol. 16, Fasc. 4 (1986)

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Mammifères de l'Ilerdien Moyen (Eocène inférieur) des Corbières et du Minervois (Bas-Languedoc, France). Systématique, Biostratigraphie, Corrélations.
Bernard Marandat
Published online: 25/01/1991

Keywords: Biostratigraphy; Corbières; correlations; Early Eocene; Ilerdian; Mammalia; Minervois; Paleobiogeography; Southern France

https://doi.org/10.18563/pv.20.2-3.55-144

  Abstract

    Mammal-bearing localities have been discovered in the marine and lacustrine series of the middle Ilerdian (Lowermost Eocene) from Southem France (Minervois and Corbières). In the localities of Fordones, Monze, Fournès, and La Gasque, thirty mammal species have been identified. Among others, they include ischyromyid rodents (Microparamys and Pseudoparamys), paromomyid and adapid primates (Arcius and Donrussellia), new insectivores, condylarths, and a dyspternine pantolestid. These faunas provide new informations on the early Eocene Mesogean faunas of Rians and Palette. The assemblages of primates and rodents from Fordones support good  correlations with Palette which was recently placed near the standard-level of Dormaal (MP 7). In fact, Palette and Fordones could be even older than Dormaal. Consequently, there seems to be a relatively important temporal gap between the late Paleocene of Cernay and the Sparnacian of Dormaal. This gap could be partly filled with the Mesogean faunas of Palette, Fordones, and Silveirinha. On the basis of these new mammal faunas the marine middle Ilerdian is proved to be older than the Cuisian stage of the Paris Basin. With regards to the position of the Fordones fauna at the top of the NP 10 calcareous nannoplankton biozone, the westem European paleomammalogists Paleocene/Eocene boundary could be situated between the NP 9 and NP 10 biozones. 


  PV article infos

Published in Vol. 20, Fasc. 2-3 (1991)

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Les crocodiliens paléogenes du Tilemsi (Mali): un aperçu systématique
Eric Buffetaut Logo
Published online: 01/10/1980

Keywords: Crocodilians; Dyrosoridae; Eocene; Mali; Palaeocene

https://doi.org/10.18563/pv.9.ext.15-35

  Abstract

    Abundant crocodilian fossil remains have been collected, mainly by R. Lavocat. from several levels of the
    Palaeogene of the Tilemsi valley (eastern Mali). Several dyrosaurids occur in the Palaeocene (Montian ?) : Phosphatosaurus sp., Hyposaurus bequaerti (Dollo). H. wilsoni (Swinton). H. nopesai (Swinton), Rhabdognathus rarus Swinton, R. compressus n. sp. ln the lower Eocene has been found a dyrosaurid which cannot be accurutely determined.In the middle Eocene were found a dyrosaurid, Tilemsisuchus lavocati n. g., n. sp., and an indeterminate eusuchian. 


  PV article infos

Published in Vol. 9, Ext (1980)

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La Poche à phosphate de Ste-Neboule (Lot) et sa faune de vertébres du Ludien Supérieur. 3- Chéloniens
France de Broin Logo
Published online: 25/09/1978

Keywords: Eocene; Quercy Phosphorites

https://doi.org/10.18563/pv.8.2-4.181-184

  Abstract

    The few remains recently collected at Ste Néboule (upper Eocene) belong to three genera: the Testudinid Ergilemys, of which it is the oldest occurence in Western Europa, probably Palaeochelys and an unpublished genus, which is peculiar to the Phosphorites du Quercy. Some statements are made on the chelonian fauna as a whole in that région. After the study of some characters proper to the genus Ergilemys, some remarks are made concerning its antecedents and descendants. 


  PV article infos

Published in Vol. 08, Fasc. 2-4 (1978)

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 Les Affinités de Nyctereutes megamastoides (Pomel), canidé du gisement Villafranchien de Saint-Vallier (Drôme, France).
R. Martin
Published online: 31/01/1971

Keywords: Canidae; Nyctereutes; Villafranchian

https://doi.org/10.18563/pv.4.2.39-58

  Abstract

    Nyctereutes megamastoides (Pomel) from the Villafranchian of the Auvergne and from Saint-Vallier presents cranial and dental characters sufficiently close to those of the late Pliocene canid from Perpignan (Roussillon), described by Depéret under the specific name of Canis donnezani belonging to the same genus Nyctereutes. The extinction of the European "Nyctereutes" group seems due to the too great alimentary specialization of this canid, whereas the Asiatic lineage represented in the Villafranchian by Nyctereutes sinensis Schlosser and at present by Nyctereutes procyonider Gray was able to maintain itself probably by means of a profound change in its alimentary regime. 


  PV article infos

Published in Vol. 04, Fasc. 2 (1971)

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Sur la présence de dents de mammifères (Creodonta, Perissodactyla) près de la limite Paléocène-Eocène à Hoegaarden, Belgique
Richard Smith and Jerry J. Hooker
Published online: 16/12/1996

Keywords: Belgium; Creodonta; Landenian; Mammals; Perissodactyla

  Abstract

    Amongst a collection of selachian teeth made at Hoegaarden in a marine level of Bruxellian (Lutetian) age, containing a reworked Landenian (Sparnacian) fauna mixed with a contemporaneous one, a few teeth of  terrestrial mammals have been discovered. They comprise two rare European taxa: ? Hallensia sp. and Palaeonictis gigantea, both known from the Landenian. Even though the ?Hallensia has not been definitely identified, il differs from the only perissodactyl of this age previously recorded from Belgium (Cymbalophus cuniculus). 


  PV article infos

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

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Eléments nouveaux sur l'évolution des genres Eucricetodon et Pseudocricetodon (Eucricetodontinae, Rodentia,Mammalia, de l'Oligocène d'Europe Occidentale.
Bernard Comte
Published online: 01/07/1985

Keywords: evolution; Occidental Europe; Oligocene; Rodentia; Systematics

https://doi.org/10.18563/pv.15.1.1-68

  Abstract

    The review of material recently collected in the new localities from the “Phosphorites du Quercy", and different localities from the South of France, bring new informations on the genus Eucricetodon THALER. 1966, and Pseudocricetodon  THALER,  I969 (Middle and Upper Oligocene. Western Europe). Thanks to Eucricetodon huerzeleri VIANEY-LIAUD, 1972, which were unsufficiently known until now, is proposed. During the middle Oligocene Eucricetodon atavus  MISONNE, 1957 seems to give rise to two lineages. One of them led to Eucricetodon huberi,which however exhibits a larger size and a development of progressive characters on the teeth. The other would be Eucricetodon huerzeleri well differentiated at the “Mas de Pauffié" standard level (beginning of the upper Oligocene). The ornementation of lower incisors is described, when possible. Though the fossils are not abundant, it seems that the ancestral lineage, Eucriretodon atavus, remains in  the upper Oligocene (Boningen standard level). evolving into Eucricetodon praecursor SCHAUB, 1925 (Rickenbach standard level). The characters of Eucricetodon dubius  (SCHAUB. 1925), represented by a numerous population in Pech Desse and Pech du Fraysse (Quercy). confirm that this species and Eucricetodon praecursor  belong to two different lineages. As Eucricetodon dubius shows more primitive features, this species could not originale from Eucricetodon atavus -Eucricetodon huberi. The appearance of this species at the level of Mas de Pauffié could be the result of an immigration. A new definition of Pseudocricetodon incertus (SCHLOSSER. 1884) is given. This species has been found in several localities, where it had not been identified until now. lts comparison with Pseudocricetodon moguntiacus  (BAHLO. l975), found at several localities from the standard level of Antoingt (end of middle Oligocene). shows a parallel evolution to that of Pseudocetodon incertus, which is  of larger size and with a less complicated pattern of teeth. 


  PV article infos

Published in Vol. 15, Fasc. 1 (1985)

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Contributions à l'étude du gisement Miocène supérieur de Montredon (Hérault). Les grands mammifères. 6 - Les périssodactyles Rhinocerotidae
Claude Guérin
Published online: 15/11/1988

Keywords: Aceratherium; anatomy; Biostratigraphy; Dicerorhinus; Miocene; Montredon; Paleoecology; Upper Vallesian

https://doi.org/10.18563/pv.18.ext.3-7-134

  Abstract

    The Montredon site has yielded about hundred rhinoceros remains:
    - twenty two of them, including 14 carpal and tarsal bones and 6 complete metapodials, belong to
    Dicerorhinus schleiermacheri at its second evolutionary stage;
    - fifty one remains including a nearby complete but crushed skull, a mandible, 26 isolated cheek-teeth, 10 carpals and tarsals, one metacarpal, are of Aceratherium incisivum, second evolutionary
    stage;
    - fifteen remains belong to Aceratherium (Alicornops) simorrense (among other an upper molar, 8 carpals and tarsals, one metatarsal);
    - six remains are attributed to an undetermined species of what is probably the most recent Prosantorhinus ever found.
    The evolution stages of the two first species allow us to date the deposit back to the Upper Vallesian, MN 10 zone; Montredon is one of the youngest sites in which Aceratherium simorrense was found. The four rhino species indicate a swampy forest biotope 


  PV article infos

Published in Vol. 18, Ext (1988)

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Rongeurs Caviomorphes de l'Oligocène de Bolivie. 2 Rongeurs du Bassin Deseadien de Salla-Luribat.
René Lavocat
Published online: 01/08/1976

Keywords: cranium; Paleobiogeography; Rodentia

https://doi.org/10.18563/pv.7.3.15-71

  Abstract

    The fauna studied in the following work involves the dentitions and skulls more or less complete of 5 genera, among which only Cephalomys was previously known by its skull. One must notice that the Salla's species of this genus is a new one. Sallamys, rather small, shows a dentition rather similar to that of Platypittamys Wood from Patagonia. The upper molars, more primitive than those of this last genus, according to the smaller dimensions of the hypocone, retain a distinct metaloph. This metaloph tends to be reduced in a way which may give us a possibility to understand how it disappeared in Platypittamys. The upper P4 can be compared as well to that of Platypittamys as to that of Gaudeamus from the African Oligocene. The lower P4, more molarized than that of Platypittamys, is already moving towards the miocene type of structure. The infraorbital foramen is wide and the insertion of the masseter on the muzzle is spacious. Branisamys, genus of a great size, shows an auditory region partly preserved, peculiarly the promontorium with the fenestra rotunda, entirely of the Hystricognathi type. Upper molars are very clearly pentalophodont. A new reconstruction is proposed for the tooth called Villarroelomys by Hartenberger. This tooth is shown to be a lower D4, perhaps of Branisamys , certainly of a rather nearly allied form, and Hartenberger does agree with the essential part of this new conclusion. Of Incamys, two incomplete skulls are known, each one being admitted to be the type of a distinct species, the first one being I. bolivianus, I. pretiosus the second. The infraorbital foramen is of a great size and the impression of the masseter on the muzzle is spacious. The sphenopalatine foramen is widely developed and of a really very uncommon great size. Only Thryonomys from Africa shows a similar tendency to the enlargement of this foramen, but not so extreme. The main basicranial foramina can be observed. The upper teeth, hemi-hypsodont, show, either a vestigial metaloph, similar to that of recent Thryonomys from Africa, associated with a well developed mesoloph, either a well developed metaloph, while the mesoloph is reduced or absent. Cephalomys was previously known by anterior parts of the skull showing a wide infraorbital foramen and a spacious facial insertion of the masseter. Its lacrymal is of the phiomorph type and the spheno-palatine foramen is seemingly of great size, like in Incamys. The species is new. The varied peculiarities of the upper teeth of these genera can be easily understood if we refer to the plan of the teeth of Phiomys andrewsi from the Oligocene and Miocene of Africa. The structure of this genus, clearly more primitive, still typically brachyodont, shows and clearly explains the fundamental coherence of the varied realisations arised from such a structure. Luribayomys n.g. is known only by an anterior half of a skull without teeth. It is remarquable by the great development of the masseter's insertions on the muzzle and by the lacrymal region, well preserved, typically phiomorphid. The classification previously published by A.E. Wood and B. Patterson is granted in its essential parts, provisionally, but not as a definitive solution. Nevertheless the Dasyproctidae are integrated within the Cavioidea, following the conclusions of Bugge and of Vucetich, reached independently. The conclusion emphasizes the exceptional meaning of the fauna of Salla-Luribay. This shows that Platypittamys, while interesting, can no more be supposed certainly representative of the normal structure of the Oligocene Caviomorph, and not even of their ancestors. The anatomical peculiarities exhibited in these new samples, auditory region, lacrymal, spheno-palatine foramen, reinforce the primitive structural identity with the Phiomorpha. Similarly, the new lower D4 favour very close relationships, ever if the affinities of the D4 has been questioned or minimized by Wood and Patterson. It is certainly possible to admit that parallelism could explain limited similarities, like the presence in North America of Rodents with an hystricomorph type of infraorbital foramen and an hystricognath mandible. But if the parallelism could be a sufficient explanation of the identical association of multiple and complete structures observed in the Caviomorpha and Phiomorpha, all the Zoological systematic would have to be questioned. The last positions of A.E. Wood on the subject (1975) are revised and criticised, and the recent publications studying the problems of distance between Africa and South America in Eocene time, as a consequence of the drift, are quoted; the possibility of transportation by rafts is shown. A new hypothesis is proposed about the interrelationships of Pentalophodont Rodents, with interesting paleobiogeographic implications. 


  PV article infos

Published in Vol. 07, Fasc. 3 (1976)

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Page 12 of 19, showing 20 record(s) out of 365 total