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Experimental taphonomy inavian eggs and eggshells: effects on early diagenesis.
Ana M. Bravo, D. A. Buscalioni, Lauro Merino and B. G. Müller
Keywords: archosaurian eggshells; avian egg; Experimental taphonomy; geochemical analysis; pyritisation; Upper Cretaceous
 
  Abstract

    We experimentally explore the early taphonomic stages involving the decay and biodegradation of buried eggs and eggshells. Unfertilised commercial chicken eggs and eggshell fragments were buried in plastic containers and were kept under controlled conditions for eight months. Half of the containers were filled with marl, and the remainder with sand. All were saturated with fresh tap water, acidified water, sulphate water, or seawater. They were kept in the dark at 23.4-26 °C, except one, which was kept in a heating chamber at 37.4°C. We expected that different burial conditions would produce distinct taphonomic outcomes. Instead, the taphonomic alterations of buried eggs parallel that of the alteration of egg proteins (i.e., denaturation and/or putrefaction) with an additional role played by the eggshell. Mummification, encrustation, distortion and fragmentation, and necrokynesis (vertical displacement) depend on organic matter decay. The experiment identifies environmental conditions that may favour or actively promote these taphonomic processes. Of these, early pyritization is one of the most relevant. For comparative purposes, samples of fossil and extinct eggshell representing three distinct environmental burial conditions were examined. These included Megaloolithus, Caiman crocodilus, and Struthio camelus ootypes. The geochemical analysis of these eggshells showed no significant differences among the chemical variables of these fossil and extant ootypes. Eggshells exhibited a stable composition over a range of experimental conditions. 
      


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

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Evolution et extinction des reptiles marins au cours du Mésozoïque.
Nathalie Bardet
Keywords: Crocodiles; evolution; Extinctions; faunal assemblages; Helveticosaurs; Hupehsuchians; Ichthyoaurs; lizards; Marine Reptiles; Mesozoic; Nothosaurs; Pachypleurosaurs; Placodonts; Plesiosaurs; Snakes; Thalattosaurs; Turnovers; Turtles
 
  Abstract

    An interpretation of the marine reptile fossil record, based on the existing litterature and complemented by the review of ancient collections and the study of new material, permits a better understanding of Mesozoic marine ecosystems. An inventory of the marine reptiles known from the Lower Triassic to the Paleocene is presented: 46 families, about 200 genera and 400 species have been recorded. This data base includes commentaries about systematics, stratigraphical ranges and geographical distribution of taxa. Marine reptiles include a mosaic of not necessarily closely related groups: ichthyosaurs, thalattosaurs, hupehsuchians, pachypleurosaurs, placodonts, nothosaurs, plesiosaurs, pliosaurs but also crocodiles, lizards, snakes, turtles. The diversity studies reveal that the fossil record of marine reptiles has been punctuated by two mass extinctions, during the Middle-Upper Triassic transition and at the Cretaceous-Tertiary boundary. The Jurassic-Cretaceous and Cenomanian-Turonian boundaries (the latter marked by the disappearance of ichthyosaurs) are potential crisis periods, but current data are not sufficient to reach conclusions. The Ladinian-Carnian transition is characterized by the disappearance of 64 % of families and affects essentially coastal forms. This extinction coincides with an important regressive phase. During the Upper Triassic, a faunal reorganisation within marine reptiles leads to the progressive disappearance of near-shore forms and to the development of pelagic groups. During the Maastrichtian-Danian crisis, 36% of families died out. Large-sized pelagic forms such as mosasaurs and elasmosaurs were the most affected and their extinction seems to have been rather sudden. On the other hand, pliosaurs and protostegid turtles became extinct, but were already declining. The survivors were near-shore forms such as crocodiles, snakes and some turtles and they may have taken refuge in freshwater environments. A break in the food chain based on phytoplankton is proposed as an extinction scenario for pelagic forms.

      


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Published in Vol. 24, Fasc. 3-4 (1995)

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Contributions à l'étude du gisement Miocène supérieur de Montredon (Hérault). Les grands mammifères. 7 - Les proboscidiens Deinotheriidae
Heinz Tobien
Keywords: allometry; Astaracian; Deinotherium; Montredon; systematics; taphonomy; Vallesian
 
  Abstract

    Some complete tooth rows and about one hundred isolated teeth enabled the identification of the deinothere of the Vallesian site Montredon (Hérault) as Deinotherium giganteum KAUP 1829, mainly by comparisons with the likewise Vallesian sample of the type locality Eppelsheim (Rheinhessen, F.R.G.).
    Scatterdiagrams of the teeth show the importance of allometry during the phyletic size increase of the European deinotheres.
    Some taphonomic problems of the Montredon deinothere are briefly mentioned. 


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Published in Vol. 18, Ext (1988)

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An unusual cranial fossil of the giant lower Pliocene shrew (Paranourosorex gigas Rzebik-Kowalska, 1975) from Podlesice, Poland
David L. Harrison and Barbara Rzebik-Kowalska
Keywords: Mammalia; Paranousorex gigas; Pliocene; Poland; Ruscinian; Soricidae
 
  Abstract

    A well-preserved anterior cranium of Paranourosorex gigas RZEBIK-KOWALSKA, 1975 from Podlesice, Poland, provides additional knowledge of this rare shrew, including almost complete maxillary dentition. The systematic status of this species as a relative of recent Anourosorex MILNE-
    EDWARDS, 1870 is confirmed 


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

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The paramyid rodent Ailuravus from the middle and late Eocene of Europe, and its relationships
Albert E. Wood
Keywords: Ailuravinae; Rodentia
 
  Abstract

    The complex taxonomic history of the paramyid rodent genus Ailuravus is reviewed. It has been described as Hyracotherium, as a creodont carnivore and as a lemuroid primate - errors at the ordínal level that are most unusual for a rodent. The genus is a member of the poorly known subfamily Ailuravinae, probably derived from some European Early Eocene species of Paramys. Aíluravus was a large arboreal paramyid with highly rugose cheek teeth, very well developed hypocone, and a remarkably weak lower incisor. It was tropical to subtropical. Three named species are recognized, A. macrurus from the Lutetian of Messel; the genotype, A. picteti, from Egerkingen, Buchsweiler and the Geiseltal, slightly later in the Lutetian; and A. stehlinschaubi, new name, from the Bartonian of Mormont-Eclépens and Robiac. One or more unnamed species are present in the Ypresian of Cuis. The species are close to a phyletic sequence. No later representatives of the genus are known. The late Eocene to earliest Oligocene North American paramyid Mytonomys, whose relationships have been obscure, is tentatively referred to the Ailuravinae. 


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Published in Vol. 07, Fasc. 1-2 (1976)

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La poche à phosphate de Ste-Néboule (Lot) et sa faune de vertebres du Ludien supérieur. 12- Fissipèdes (Carnivores)
Louis de Bonis
Keywords: Carnivora; Eocene; Quercy phosphorites
 
  Abstract

    Les Carnivores Fissipèdes de Sainte-Néboule appartiennent tous au genre Cynodictis et semblent constituer une population homogène. Celle-ci se distingue suffisamment des espèces déjà décrites pour constituer un taxon particulier : Cynodictis lacustris neboulensis n. s. sp. . L'étude des variations à l'intérieur de cette population nous a conduit à reconsidérer les critères utilisés pour définir les espèces existantes et à regrouper certaines d'entre elles. Il semble qu'il demeure cependant trois lignées distinctes dans le genre Cynodictis mais le matériel nous paraît encore insuffisant pour traduire cette remarque en termes de systématique. 


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

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The Ctenodactylidae (Rodentia) from the Oligocene of Ulantatal (inner Mongolia, China)
Monique Vianey-Liaud, Norbert Schmidt-Kittler and Laurent Marivaux
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. 


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

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Les oiseaux aquatiques (Gaviiformes à Anseriformes) du gisement Aquitanien de Saint-Gerand-le-Puy (Allier, France): Révision systématique.
Jacques Cheneval
Keywords: Aves; Early Miocene; Osteology; Palaeoecology; systematics
 
  Abstract

    Six orders of birds adapted to aquatic life are represented among the numerous avifauna of "Saint-Gérand-le-Puy": Gaviiformes, Procellariiformes, Pelecaniformes, Ciconiiformes, Phoenicopteriformes, and Anseriformes. The present study of this avifauna proposes several changes in systematics:- Procellariiformes: Puffinus arvernensis does not belong in Procellariidae but in Diomodeidae, and it is transferred to the fossil genus Plotornis previously described in the Middle Miocene of France. - Pelecaniformes: Phalacrocorax littoralis remains in Phalacrocoracidae; P. míocaenus is different from the modern species, and is transferred to the new genus Nectornis. Empheresula arvernensis, described in the Oligocene deposits of Gannat, seems to be present in Saint-Gérand-le-Puy too. Pelecanus gracilis shows many differences from the modern species, and belongs to the new genus Miopelecanus, - Ciconiiformes: Ardea formosa nom. oblit. is a synonym of Proardeola walkeri. - Anseriformes: a new species closely related to swans is described, and belongs to the fossil genus Cygnopterus, of the Middle Oligocene of Europe; this species is called C. alphonsi. The ecology of each species is suggested by comparison with that of its nearest living relatives, and by study of osteological adaptations. 


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Published in Vol. 14, Fasc. 2 (1984)

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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
Keywords: evolution; Occidental Europe; Oligocene; Rodentia; systematics
 
  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. 


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

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Contributions à l'étude des micromammifères du gisement Miocène supérieur de Montredon (Hérault). 4 - Les chiroptères
Bernard Sigé
Keywords: Chiroptera; Hérault; Late Miocene; Micromammals; Montredon
 
  Abstract

    The Montredon local fauna yielded very rare bats, represented by damaged isolated teeth. Only a few documents are available for this period of the European Neogene. ln this poor state of knowledge, the material represents three undetermined species, a supposed molossid and two vespertilionids. 


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

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First Neogene Otonycteris (Chiroptera: Vespertilionidae) from Ukraine: its biostratigraphic and paleogeographic significance.
Valentina V. Rosina
Keywords: bats; East Europe; Gritsev; Late Miocene; Mammalia

doi: 10.18563/pv.39.1.e2
 
  Abstract

    A new species, Otonycteris rummeli nov. sp., is described from the Late Miocene site Gritsev (MN 9) in the Ukraine. Otonycteris rummeli nov. sp. differs from those of most vespertilionids, except recent Otonycteris, Antrozous and Early Miocene Karstala silva, in having a well-developed entocingulid at the foot of the trigonid valley in the lower molars. The morphological resemblance of Otonycteris, Antrozous and Karstala is apparently a case of convergence in the evolution of the Old and New Worlds bat faunas. From at least the Middle Miocene the range of Otonycteris distribution spread to the whole of Central Europe and such a situation continued during the whole Late Miocene. This indicates a more arid climate in Europe during the Upper Miocene compared to the Quaternary. The reduction of the distribution range of Otonycteris and its extinction in most of the territory of Europe could have been caused by the global climatic cooling and increasing glacial cycle amplitude during the onset of the Quaternary. 


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Published in Vol.39-1 (2015)

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Cricetid rodents from Siwalik deposits near Chinji village. Part I: Megacricetodontinae, Myocricetodontinae and Dendromurinae.
Everett H. Lindsay
Keywords: Dendromurinae; Megacricetodontinae; Middle Miocene; Myocricetodontinae; Rodents; Siwalik
 
  Abstract

    Seventeen species of cricetid rodent are recognized and described from lower and middle Siwalik deposits in the Potwar Plateau of Pakistan. These species are grouped in three categories, characterized as subfamilies (e. g., Megacricetodontinae, Myocricetodontinae, and Dendromurinae); an additional and more abundant category of rodents from these deposits, the Democricetodontinae, is excluded from this study, and will be described in a later study. Fifteen of the species are new, and four new genera are described. The Siwalik cricetid taxa are : Megacricetodon aquilari, n. sp.; Megacricetodon sivalensis, n. sp.; Megacricetodon daamsi, n. sp.; Megacricetodon mythikos, n. sp.; Punjabemys downsi, n. gen. & n. sp.; Punjabemys leptos, n. gen. & n. sp.; Punjabemys mikros, n. gen. & n. sp.; Myocricetodon sivalensis, n. sp.;  Myocricetodon sp.; Dakkamyoides lavocati, n. gen. & n. sp.; Dakkamyoides perplexus, n. gen. & n. sp.; Dakkamys asiaticus, n. sp.; Dakkamys barryi, n. sp.; Dakkamys sp.; Paradakkamys chinjiensis, n. gen. & n. sp.; Potwarmus primitivus, n. gen.; and Potwarmus minimus, n. gen. & n. sp. This diverse record of middle Miocene small mammals illuminates a profound radiation of cricetid rodents in southem Asia, the effects of which were felt in Europe and Africa as well as the rest of Asia. 


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Published in Vol. 18, Fasc. 2 (1988)

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Arvicolinae (Rodentia) du Pliocène terminal et du quaternaire ancien de France et d'Espagne.
Jacques Michaux
Keywords: Arvicolinae; France; Pleistocene; Pliocene; Spain

doi: 10.18563/pv.4.5.137-214
 
  Abstract

    Two steps can be distinguished in the history of the first invasion of western and south western Europe by the arvicolines. The first step corresponds to the installation of these rodents with the immigration of Promimonys inxuliferus Kowalski, then of Mimomys stehlini Kormos and of Mimomys gracilis (Kretzoi). The second is characterized by the establishment of a geographic differentiation in the arvicoline fauna between the south of France and Spain, from where are described new species of Mimomys (Mimamys cappettai, Mimomys septimanus, Mimonys medasensis), and the rest of France, where are found only elements already known from central Europe or England (Mimomys polonicus Kowalski, Mimomys pliocaenicus F. Major, Mimomys reidi Hinton, or forms very close to the latter). This geographic differentiation, which is very certainly the consequence of the division of Europe into distinct climatic provinces, one of them being the southern province comprising at least Spain and southern France, could result from a cladogenetic evolution of Mimomys stehlini and Mimomys gracilis after their immigration. The present work is also a contribution to the search for correlations between the diverse micromammal localities of the latest Pliocene (or early Villafranchian) and of the early Quaternary of Europe. 


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Published in Vol. 04, Fasc. 5 (1971)

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Nouveaux gisements à rongeurs dans les molasses oligo-miocènes de la région toulousaine
Francis Duranthon
Keywords: Cricetidae; Eomyidae; GIiridae; Miocene; Oligocene; Rodents; Sciuridae; Southern France
 
  Abstract

    The fauna from three new rodent localities (Castelmaurou, Grépiac-carrière et Grépiac-rive gauche) from Oligo-Miocene molasses of the Toulouse area is described. The one from Colomiers is completed. 11 species belonging to 4 families (Cricetidae, Eomyidae, Gliridae, Sciuridae) are present. The Miocene localities of Grépiac-carrière and Colomiers are correlated with Balizac, La Brète, Lambert and Lespignan. Grépiac-rive gauche is just a little older than these sites. Castelmaurou is somewhat younger than La Milloque and belongs to Oligocene. 


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Published in Vol. 22, Fasc. 2-3 (1993)

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La plus ancienne faune de mammifères du Quercy : Le Bretou
Jean-Louis Hartenberger, Bernard Sigé and Jean Sudre
Keywords: Le Bretou; Quercy phosphorites
 
  Abstract

    Abstract not available 


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Published in Vol. 06, Fasc. 3-4 (1975)

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Présence de Palaeobatrachidae (Anura) dans des gisements tertiaires Français caractérisation, distribution et affinités de la famille
Colette Vergnaud-Grazzini and Robert Hoffstetter
Keywords: Anura; Palaeogeography; systematics
 
  Abstract

    The Palaeobatrachidae until now have not been reported from France. The present note makes known the discovery of very significant remains in three Tertiary localities of France: Cernay (late Paleocene), Laugnac (late Aquitanian) and Sansan (middle Helvetian). The osteologic characters, as well as the geographic and stratigraphic distribution of the family are re-stated with added details. The Palaeobatrachidae are a European family known from the late Jurassic of Catalonia (publication in course by J. Seiffert) to the Plio-Pleistocene (pre-Mindel) of Poland and Rumania. By their way of life and certain osteologic characters they are similar to the Pipidae, but they are distinguished by profound differences. It would be rash to include them in the Pipoidea or even in the Aglossa. They are apparently an independant group, essentially holarctic, which held in Europe a role equivalent to that played by the Pipidae south of Tethys. 


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Published in Vol. 05, Fasc. 4 (1972)

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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.  


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

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La poche à phosphate de Ste-Néboule (Lot) et sa faune de vertebres du Ludien superieur. 14 - Conclusions générales
Jean-Louis Hartenberger
Keywords: Eocene; Quercy phosphorites
 
  Abstract

    Le matériel provenant de nouvelles fouilles dans les phosphorites du Quercy, soumis aux divers spécialistes, a conduit à la soutenance de plusieurs thèses d'état: sur les rongeurs (Hartenberger, Vianey-Liaud), les Chiroptères et Insectivores (Sigé), les Artiodactyles (Sudre), les Squamates (Rage) et, en partie, les Chéloniens (De Broin). Chacun dans son domaine, à côté des conclusions d'ordre évolutif, paléogéographique ou paléoécologique, a pu établir des successions stratigraphiques des gisements du Quercy qui se sont révélées largement concordantes. Ainsi la succession des faunes du Quercy est actuellement l'une des mieux établies. Dans ce contexte, les différents spécialistes ont décidé de conjuguer leurs efforts dans l'étude monographique de plusieurs gisements repérés le long de cette échelle, afin de rassembler l'information paléontologique sur des faunes bien précises et de tenter d'obtenir des indications d'ordre taphonomique. 


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

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A new Desmodillus (Gerbillinae, Rodentia) species from the early Pliocene site of Langebaanweg (South-western Cape, South Africa)
 
Christiane Denys and Thalassa Matthews
Keywords: Lower Pliocene; Muridae; Rodentia; RSA

doi: 10.18563/pv.41.1.e1
 
  Abstract

    Situated in the Cape region of the Republic of South Africa (RSA), the paleontological site of Langebaanweg is dated to 5.1 Myr and is famous for having yielded an abundant vertebrate assemblage, including numerous rodent species from the Mio-Pliocene transition. Based on molar morphology and skull anatomy, the single Gerbillinae taxon identified at Langebaanweg and described in this paper is allocated to Desmodillus, which is a modern monotypic South African endemic genus. It is significant in being the oldest representative of the genus in Africa. We describe here a new species of this genus which is larger than the modern D. auricularis, but nevertheless retains some of its main characteristics, namely the shape of the maxilla and mandible, the presence of poorly fused alternating cusps, and no longitudinal crest. This taxon differs from modern South African Gerbilliscus representatives in some mandibular and maxillary characters, in the m1 prelobe cusp, and in having less fused cusps. Two fossil Gerbillinae discovered in the Upper Miocene of Africa and Asia, Abudhabia and Protatera, have been compared with the new species. We discuss their relationships with modern and Plio-pleistocene Gerbillinae and conclude that Abudhabia could be the sister taxon of Desmodillus and that around 6-5 Myr a vicariance event allowed Gerbillinae to diversify into modern Desmodillus in South Africa, and Gerbilliscus in East Africa. The murine/gerbilline ratio, which is a good indicator of rainfall, supports other proxies which suggest that at 5.1 Myr the climate in the Langebaanweg region was more humid than today. 


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Published in Vol 41-1 (2018)

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S.I. Data
New datation of the Tafna Basin (Algeria): A combination between biochronological and magnetostratigraphical data
Salamet Mahboubi, Mouloud Benammi and Jean-Jacques Jaeger
Keywords: correlations; Late Miocene; North Africa; Rodentia

doi: 10.18563/pv.39.1.e1
 
  Abstract

    The Tafna Basin corresponds to the lowlands, which are located in front of Tessala and Traras ranges, below the Tlemcen mountains, Algeria. This basin displays a complete sedimentary cycle dominated by lagoonal-fluvial and marine deposits. The continental formations located at the base of these deposits are mainly composed of alternating sandstones and clays. An early late Miocene age has been previously attributed to them, based on direct correlations with marine deposits. Search for micromammal fossils led to the discovery of three different rodent species from a single level of the Djebel Guetaf section, located at the bottom of these deposits. The rodent assemblage indicates a late Miocene age. Combined magnetostratigraphical and biostratigraphical investigations were carried out to provide a more accurate age control of these continental deposits. Sixty-four oriented rock samples were collected for a magnetostratigraphic study along a 92 meters thick section including the fossiliferous layer. Rock magnetic investigations indicate the presence of both high and low coercivity minerals. Specimens subjected to progressive thermal demagnetization procedures show that the samples exhibit a high temperature magnetization component and display a normal polarity. Based on biostratigraphic constraints, the Guetaf section is correlated with Chron C4An, indicating an age ranging from
    9.1 to 8.7 Myr.
      


  Article infos

Published in Vol.39-1 (2015)

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