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Page 16 of 19, showing 20 record(s) out of 365 total

Le genre Mesembriacerus (Bovidae, Artiodactyla, Mammalia) : un Oviboviné primitif du Vallésien (Miocène supérieur) de Macédoine (Grèce)
Geneviève Bouvrain and Louis de Bonis Logo
Published online: 15/12/1984

Keywords: Bovidae; Cladistics; Late Miocene; Ovibovinae; Vallesian

https://doi.org/10.18563/pv.14.4.201-223

  Abstract

    The bovid Mesembriacerus melentisi, the numerous skulls, teeth and limb bones of which are described from the locality Ravin de la Pluie (Macedonia, Greece), bears some features which allow us to put it in the tribe ovibovini (Ovibovinae) with several other Miocene genera and the Recent one Ovibos. A cladogram gives the phyletic relationships within this tribe. It shows that Mesembriacerus which is one of the oldest genera, is also the most primitive. The limb bones are as elongated as those of Recent cursorial bovids and they show, as does the bulk of the fauna, an open environment for the locality. 


  PV article infos

Published in Vol. 14, Fasc. 4 (1984)

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Les oiseaux aquatiques (Gaviiformes à Anseriformes) du gisement Aquitanien de Saint-Gerand-le-Puy (Allier, France): Révision systématique.
Jacques Cheneval
Published online: 01/11/1984

Keywords: Aves; Early Miocene; Osteology; Palaeoecology; Systematics

https://doi.org/10.18563/pv.14.2.33-115

  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. 


  PV article infos

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

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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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Les vertébrés fossiles de Colombie et les problèmes posés par l'isolement du Continent sud-Américain.
Jaime de Porta
Published online: 20/01/1969

Keywords: Columbia; Cretaceous; Fauna; Quaternary; South America

https://doi.org/10.18563/pv.2.2.77-94

  Abstract

    A general view is given of the vertebrate faunas, Cretaceous to Quaternary of age, found in Columbia and of their principal characteristics. This view leads to the discussion of the isolation of the South American continent and of the role played by the Bolivar syncline with respect to North American immigrants during the Oligocene. The absence of marine deposits of Oligocene age in the north and northwest of Columbia suggests the possibility of a communication with Central America. This communication would have permitted the passage of hystricomorph rodents, of platyrrhine monkeys, and of colubrids. The non-occupation, until then, of the ecologie niches of these groups would have favored their installation beside the indigenous fauna. In this hypothesis it would no longer be necessary to admit that these vertebrates arrived as «island hoppers ››. The eco-biologic conditions would explain the absence of large-sized forms of North American origin. 


  PV article infos

Published in Vol. 02, Fasc. 2 (1969)

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Essai de filiation des campagnols et des lemmings (Arvicolidae, Rodentia) en zone holartique d'après la morphologie dentaire.
Jean Chaline
Published online: 01/10/1980

Keywords: Arvicolidae; Dental morphology; Paleogeography; phyletic relationships

https://doi.org/10.18563/pv.9.ext.375-382

  Abstract

    The Arvicolid evolution results in an increase of the dental structure complexity. The M3/ differenciation seems to characterise the tribe subdivisions, that of M/1 being variable from one to another lineage. The phyletic relationships of fossil lineages are discussed from a paleogeographic point of view. 


  PV article infos

Published in Vol. 9, Ext (1980)

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Révision des Rhombodontidae (Neoselachii Batomorphii) des bassins à phosphate du Maroc
Abdelmajid Noubhani and Henri Cappetta Logo
Published online: 20/05/1994

Keywords: Batomorphii; Maastrichtian; Morocco; New taxa; Phosphate; Rbombodontidae

https://doi.org/10.18563/pv.23.1-4.1-49

  Abstract

    The revision of the Rhombodontidae from the Maastrichtian of Morocco led us to the description of a new species: Rhombodus andriesi.

    The biometrical study of populations of R. binkhorsti and R. microdon, species sometimes considered as synonymous, supports the conclusion that they represent two distinct species and not young and adult specimens of a single species. The stratigraphical range of these two species confirms this
    result.

    The reexarnination of type-series studied by C. Ararnbourg led us to revise the generic status of Rhombodus bondoni which is now ranged, because his dental features, in the new genus Dasyrhombodus showing a less derived dentition than Rhombodus. The stratigraphical range of each species is clarified within the phosphatic series. 


  PV article infos

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

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Contributions à l'étude du gisement Miocène supérieur de Montredon (Hérault). Les grands mammifères. 5 - Les périssodactyles Equidae
Véra Eisenmann
Published online: 15/11/1988

Keywords: Equidae; Hipparion; Late Vallesian; Mammalia; Montredon; Perissodactyla

https://doi.org/10.18563/pv.18.ext.65-96

  Abstract

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


  PV article infos

Published in Vol. 18, Ext (1988)

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The fossil rabbit from Valdemino cave (Borgio Verezzi,Savona) in the context of western Europe Oryctolagini of Quaternary.
Giulia Nocchi and Benedetto Sala
Published online: 15/12/1997

Keywords: Lagomorpha; Mammals; North-western Italy; Oryctolagus; Plio-Pleistocene; Savona

  Abstract

    The present research deals with the remains of a lagomorph found at Valdemino cave and comes to the conclusion that it is a rabbit with peculiar characteristics in comparison with the other known species Oryctolagus laynensis, O. lacosti and 0. cuniculus. We studied other fossil remains of rabbit populations from Villafranchían and middle Pleistocene deposits and compared them with data from the literature and with recent material. The analysis leads us to maintain two phylogenetic hypotheses about the history of Oryctolagini. The ñrst one, already formulated by Lopez Martinez, suggests that 0. cuniculus derives from O. laynensis,while the origin of O. lacostí is unknown; according to the second hypothesis 0. laynensis would be the common ancestor of two phyletic lineages, 0. lacosti and 0. cuniculus. In both cases the lagomorph from Valdemino would be the form derived from 0. lacosti, from which however it differs in peculiar characteristics. Since the rabbit from Valdemino survives until the beginning of Postgalerian, its disappearance may coincide with the retreat of 0. cuniculus from western Europe in Spain and, perhaps, in south-western France, before the last glaciation. O. cuniculus survived in Spain, from where it spread once again over western Europe as a result of man.

      


  PV article infos

Published in Vol. 26, Fasc. 1-4 (1997)

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Preliminary evolution of paleosols and implications for interpreting vertebrate fossil assemblages, Kuldana formation, Northern Pakistan
Andres Aslan and J. G. M. Thewissen Logo
Published online: 16/12/1996

Keywords: Eocene; Kuldana Formation; Pakistan; Paleosols; Pedogenic Carbonate; taphonomy; Time Averaging; Vertebrate Fossils

  Abstract

    Paleosols and the taphonomy of vertebrate fossils in the Eocene Kuldana Formation of northern Pakistan provide important information on the preservation and time-averaging of fossil assemblages. Morphologic, mineralogic, and chemical data as well as comparisons with Quaternary soils suggest that Kuldana paleosols formed under generally dry and oxidizing conditions over time intervals of less than 100 000 years and perhaps as short as 1000 years. The distribution of carbonate in Kuldana paleosols further indicates that the upper half of the profiles were acidic whereas the lower halves were alkaline. Vertebrate fossils are rare in Kuldana paleosols and occur primarily in well-cemented sandstones and conglomerates with abundant micritic and iron-stained nodules that were reworked from floodplain soils. The scarcity of vertebrate remains in Kuldana paleosols probably reflects a combination of acidic, dry, and oxidizing conditions in the upper half of the profiles and rapid floodplain sedimentation. Comparisons between the taphonomic characteristics of Kuldana channel fossil assemblages and bone accumulations in modem rivers provide a basis for estimating the length of time represented by Kuldana fossils from several important localities. Vertebrate fossil assemblages from Barbora Banda are characterized by a low-diversity paleofauna, partially articulated skeletons, and bones that are sorted by size and shape. Comparison with bone accumulations in modern rivers suggests that the fossils from Barbora Banda accumulated in 1 to 10 years. Vertebrate fossils from the Lower Kuldana in the Kala Chitta Hills region, typified by locality H-GSP 62, are characterized by a high-diversity paleofauna and generally random and unsorted fossil bone distributions, which suggest that the fossils from these localities represent longer time intervals than the Barbora Banda fossils. Based on the time estimates for Kuldana paleosol development, fossil assemblages in Kuldana channel deposits in the Kala Chitta Hills region probably represent time intervals of about 1000 years. 


  PV article infos

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

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Rates of evolution in divergent species lineages as a test of character displacement in the fossil record : tooth size in Paleocene Plesiadapis (Mammalia, Proprimates)
Phillip D. Gingerich Logo
Published online: 16/12/1996

Keywords: character displacement; character divergence; fractal time series; Plesiadapis; Rates of evolution

  Abstract

    Two species lineages of North American late Paleocene Plesiadapis exhibit a pattern of size divergence from a common ancestral lineage. Time series of fossils in each of these lineages are analyzed to test the idea that size divergence represents competitive character displacement. The critical factor in a test of character divergence is showing that divergent lineages evolved directionally rather than randomly (multifactorially). Analysis of evolutionary rates and their temporal scaling in Plesiadapis shows that both divergent species lineages have the scaling slope expected for lineages evolving randomly rather than directionally, and size divergence in Plesíadapis does not represent character displacement. Rates of evolution commonly observed on a per-generation time scale are high enough to produce character displacement within a few generations. Thus character displacement is not likely to be visible on scales of time that can be studied in the fossil record. 


  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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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: 30/04/2014

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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Enamel hypoplasia on rhinocerotoid teeth: Does CT-scan imaging detect the defects better than the naked eye?
Manon Hullot Logo and Pierre-Olivier Antoine Logo
Published online: 03/01/2022

Keywords: fossil teeth; method; micro-CT imaging; Rhinocerotoidea

https://doi.org/10.18563/pv.45.1.e2

  Abstract

    Micro-CT imaging is an increasingly popular method in paleontology giving access to internal structures with a high resolution and without destroying precious specimens. However, its potential for the study of hypoplasia defects has only recently been investigated. Here, we propose a preliminary study to test whether hypoplastic defects can be detected with micro-CT (μCT) scan and we assess the costs and benefits of using this method instead of naked eye. To do so, we studied 13 fossil rhinocerotid teeth bearing hypoplasia from Béon 1 (late early Miocene, Southwestern France) as positive control and 11 teeth of the amynodontid Cadurcotherium (Oligocene, Phosphorites du Quercy, Southwestern France), for which enamel was partly or totally obscured by cement. We showed that all macroscopically-spotted defects were retrieved on 3D reconstructions and selected virtual slices. We also detected additional defects using μCT scan compared to naked eye identification. The number of defects detected using μCT was greater in the Cadurcotherium dataset (paired-sample Wilcoxon test, p-value = 0.02724) but not for our control sample (paired-sample Wilcoxon test, p-value = 0.1171). Moreover, it allowed for measuring width and depth of the defects on virtual slices (sometimes linked to stress duration and severity, respectively), which we could not do macroscopically. As μCT imaging is both expensive and time consuming while not drastically improving the results, we recommend a moderate and thoughtful use of this method for hypoplasia investigations, restricted for instance to teeth for which enamel surface is obscured (presence of cement, uncomplete preparation, or unerupted germs). 


  PV article infos

Published in 45-1 (2022)

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S.I. Data
La variabilité morphologique dentaire du Landenodon (Condylarthra) de Dormaal, (Eocène,Belgique)
Marc Godinot Logo
Published online: 01/10/1980

Keywords: Condylarths; Dormaal; Early Eocene; Landenodon

https://doi.org/10.18563/pv.9.ext.167-196

  Abstract

    The study of dental variations in Landenodon from Dormaal (early Eocene, Belgium) shows that only one
    species is present in this locality : L. woutersi QUINET, 1968 (Condylarthra, Arctocyonidae, Arctocyoninae). A high morphological variability is described, especially concerning the metaconid of P/4, the paraconid of M/2, and some characters of M1/ which have been found to be independant of each other. This variability is discussed. 


  PV article infos

Published in Vol. 9, Ext (1980)

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Second international symposium on Dinosaur, Eggs and Babies (Montpellier-Aix-en-Provence, 25-29 Août 2003).
Monique Vianey-Liaud Logo
Published online: 15/12/2003

Keywords: amniotic eggshells; dinosaurs

  Abstract

    Le premier Symposium International sur les ceufs de dinosaures et leurs petits a connu un francs succès, à Isona, en Catalogne (Espagne) en 1999. I1 faisait suite à la publication en 1994 d'un premier ouvrage "Dinosaurs eggs and babies" édité par K. Carpenter, K. Hirsch et J. Homer. Entre 1994 et 1999, les nouvelles découvertes ont augmenté significativement, notamment celles d'ceufs embryonnés, et le nombre de chercheurs impliqués dans ce domaine a accompagné cet accroissement. Jusque là, l'étude de ces objets, les coquilles d'ceufs, est restée longtemps marginale, faute d'une méthodologie scientifique appropriée. 


  PV article infos

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

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Experimental taphonomy inavian eggs and eggshells: effects on early diagenesis.
Ana M. Bravo, D. A. Buscalioni Logo, Lauro Merino and B. G. Müller
Published online: 15/12/2003

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. 
      


  PV article infos

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

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L'anatomie de Lyrocephaliscus euri (wiman), Trématosaure du Trias inférieur du Spitsberg : arrière-crâne, squelette axial et ceinture scapulaire.
Jean-Michel Mazin Logo and Philippe Janvier Logo
Published online: 30/06/1983

Keywords: skull anatomy; Spitsbergen; Trematosaurs; Trias

https://doi.org/10.18563/pv.13.1-2.13-31

  Abstract

    The formic acid preparation of a nodule collected from the Lower Triassic of Spitsbergen, and containing a skull with some associated postcranial elements of Lyrocephaliscus euri (WIMAN), precises and enriches previous descriptions of the reputedly well-known trematosaur. lt permits more detailed descriptions of the occipital region, of the course of the carotid arteries and collateral vessels, and refutes the previous description of a stapedial foramen in trematosaurs. The discovery of pleurocentres associated with the other vertebral components confirms the primitive rhachitomy of trematosaurs. 


  PV article infos

Published in Vol. 13, Fasc. 1-2 (1983)

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First evidence of an early Miocene marine teleostean fish fauna (otoliths) from la Paillade.(Montpellier,France)
Bettina Reichenbacher Logo and Henri Cappetta Logo
Published online: 15/06/1999

Keywords: Aquitanian; Biostratigraphy; La Paillade; marine deposits; Miocene; otoliths; Palaeoecology; Palaeogeography; Southern France; Teleostei

  Abstract

    A fossil fish fauna, based on 5533 otoliths, from the La Paillade locality at Montpellier is described and figured. The otolith-bearing marls correlate to mammal zone MN l (Aguilar, 1982), and thus represent the earliest Miocene. The fish fauna consists of 30 taxa belonging to 20 families. Two species are new: Dussumieria sittigi and Liza gaudanti. The predominant faunal element is the Lesueurigobius vicínalis-species complex, composing 73% of all investigated otoliths. The palaeoecological analysis reveals a marine to euryhaline fish fauna living under tropical to subtropical conditions in the transition zone littoral - sublittoral. Water depth probably was more than 10 m. The scarcity of pelagic físhes suggests that the habitat was either a sheltered bay and/or far away from the open sea. Furthermore, some genera represented in the La Paillade fish fauna presently live exclusively in the Indopacific realm. Their presence strongly supports a broad connection between the Indian Ocean, the Mediterranean, and the Paratethys Seas during the Early Miocene (Aquitanian). From a palaeobiogeographical point of view, faunal relationships were found between the La Paillade fish fauna and both the Paratethys fish fauna and the fish fauna from the deposits in the Upper Rhinegraben and the Mayence and Hanau Basins (Germany).



      


  PV article infos

Published in Vol. 28, Fasc. 1 (1999)

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 La poche à phosphate de Ste-Neboule (Lot) et sa faune de vertébres du Ludien Supérieur. 1 La poche et son remplissage
Bernard Gèze
Published online: 15/09/1978

Keywords: Eocene; Quercy Phosphorites

https://doi.org/10.18563/pv.8.2-4.171-173

  Abstract

    La poche de Ste-Néboule, commune de Béduer (Lot), 15 km environ à l'WSW de Figeac, fait partie du groupe le plus septentrional des gouffres creusés par les ruissellements du Paléogène dans les calcaires jurassiques de la bordure sud-ouest du Massif Central et qui furent comblés à la même époque par des argiles sidérolithiques accompagnées de phosphate de chaux concrétionné ainsi que des restes de la célèbre faune dite «des phosphorites du Quercy» . 


  PV article infos

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

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Les Issiodoromyinae (Rodentia, Theridomyidae) de l'Eocène supérieur à l'Oligocène supérieur en Europe occidentale
Monique Vianey-Liaud Logo
Published online: 15/05/1976

Keywords: climate; Faunal turnover; Paléogène

https://doi.org/10.18563/pv.7.1-2.1-115

  Abstract

    Based on material from 30 localities, morphologic dental, cranial and biometric analyses have permitted the characterization of two parallel Issiodoromyine lineages, and also the definition of diverse species representing several evolutive stages. Thus it is that new lineages complete the contribution made by the Theridomyinae and Cricetidae and permit, for the Quercy in particular, additional precision in the biochronologic succession of the localities. One of the lineages is limited to the genus Pseudoltinomys LAVOCAT; the other evolves from the genus Elfomys HARTENBERGER to the genus Issiodoromys BRAVARD in GERVAIS. The latter is affected by profound anatomical changes due to a functional modification of the mastication apparatus. These changes seem to be able to be put in relation with the aridification and cooling of the climate at the end of the Eocene. At the end of the middle Oligocene, a new chewing structure is achieved. It is found in diverse living rodents that inhabit a rather arid steppe environment (Cavia, Pedetes, Ctenodactylus). To these supposed nearby ecologic conditions, these rodents have responded in a convergent fashion. It is possible to attribute to the extreme specialization of Issiodoromys its incapacity to adapt to the new climatic crisis of the end of the Oligocene. The arrival of immigrants may be considered as another cause of its disappearance at this time, complementary or not with the first. 


  PV article infos

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

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Page 16 of 19, showing 20 record(s) out of 365 total