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

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


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Published in Vol. 18, Ext (1988)

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A new species of hippopotamine (Cetartiodactyla, Hippopotamidae) from the late Miocene Baynunah Formation, Abu Dhabi, United Arab Emirates
Jean-Renaud Boisserie, Mathieu Schuster, Mark J. Beech, Andrew Hill and Faysal Bibi
Keywords: Arab Peninsula; Hippopotamidae; Hippopotamine event; Systematics

doi: 10.18563/pv.41.1.e2
 
  Abstract

    The discovery of new hippopotamid material from the late Miocene Baynunah Formation (Abu Dhabi, United Arab Emirates) has prompted the revision of the existing material of this as yet unnamed fossil taxon. The Baynunah hippopotamid appears to be distinct from all other contemporary and later species in having a relatively more elongate symphysis, a feature similar to the earlier (and more primitive) Kenyapotamus. Yet, the Baynunah hippopotamid presents a dentition typical of the Hippopotaminae. It is therefore a distinct species attributed to the later subfamily, described and named in this contribution. This species provides further evidence for a ca. 8 Ma evolutionary event (termed “Hippopotamine Event”) that initiated the spread and ecological significance of the Hippopotaminae into wet habitats across Africa and Eurasia. The morphological affinities of the new species from Abu Dhabi suggest that the Arabian Peninsula was not a dispersal route from Africa toward southern Asia for the Hippopotamidae at ca. 7.5 Ma to 6.5 Ma. 


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Published in Vol 41-1 (2018)

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S.I. Data
Preliminary evolution of paleosols and implications for interpreting vertebrate fossil assemblages, Kuldana formation, Northern Pakistan
Andres Aslan and J. G. M. Thewissen
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. 


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

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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.
      


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Published in Vol.39-1 (2015)

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Mammals of the Eocene locality Toru Ajgyr (Kyrgyzstan)
Jorg Erfurt and Alexander Averianov
Keywords: Eocene; Kyrgyzstan; Mammalia; Olsenia; Palaeoecology; Stratigraphy; taxonomy
 
  Abstract

    Morphological descriptions are given of Eocene mammals from the locality Toru Ajgyr (NEKyrgyzstan) that were excavated in 1997 and 1998 in a cooperation between the Martin-Luther-University Halle (Germany), the Zoological Institute in St. Petersburg (Russia) and the Seismological Institute in Bishkek (Kyrgyzstan). The species found belong mostly to perissodactyls, as Lophialetes sp., Teleolophus sp. and brontotheres. The primitive ungulate family Olseniidae is represented by a complete foot skeleton of cf. Olsenia sp. In addition, postcranial materials of Gobiatherium mirificum (Dinocerata) and of artiodactyls have been collected and are described herein. Based on mammals, the locality is part of the Asian Land Mammal Age Arshantan and is stratigraphically equivalent with the Bridgerian Land Mammal Age in North America and with the lower and middle Geiseltalian of the European Middle Eocene. 


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

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Nouvelles données sur les mammifères du Thanétien et de l'Yprésien du bassin d'Ouarzazate (Maroc) et leur contexte stratigraphique.
Emmanuel Gheerbrant, Jean Sudre, Sevket Sen, Claude Abrial, Bernard Marandat, Bernard Sigé and Monique Vianey-Liaud
Keywords: early Paleogene; magnetostratigraphy; Mammals; Morocco; North Africa; Ouarzazatz basin; Systematics
 
  Abstract

    New faunal and stratigraphical data on the vertebrates localities from the early Paleogene of the Ouarzazate Basin (Adrar Mgorn 1, Adrar Mgorn 1 bis et N'Tagourt 2), Morocco, are presented. A magnetostratigraphical study, the first for such early Paleogene Arabo-African mammal localities, and the discovery of probable remains of the nannofossil Discoaster support the Thanetian age of the Adrar Mgorn 1 site. The magnetostratigraphy suggests a slightly later age than was thought for the Paleogene formations of the local series of Tinerhir and for the vertebrate localities: late or latest Thanetian for Adrar Mgorn 1 and Adrar Mgorn 1 bis, middle Ypresian for N'Tagourt 2. It also indicates a lower position of the KT boundary in the series. Two tons of matrix recovered in the vertebrate sites have vielded new data on the micromammals. A damaged lower molar from N'Tagourt 2 is referable to Khamsaconus bulbosus  and supports the proboscidean affinities of this species and especially possible relationships with bunolophodont taxa such as elephantiforms. A lower molar from Adrar Mgorn 1 bis belongs to a new form which can be identified as a plesiadapiform or an euprimate close to Altiatlasius koulchii though significantly larger. A new material from Adrar Mgorn 1 illustrates a new dilambdodont adapisoriculid species which is referable to Garatherium : ?Garatherium todrae n. sp. Another species referred to Garatherium is known in the locality (?Garatherium n. sp.). Garatherium is a new lineage from the Ouarzazate basin which crosses the Paleocene-Eocene boundary together with Palaeoryctes, Didelphodontinae gen. and sp. 2, Todralestes, and Afrodon, and it is the first Paleocene-Eocene lineage identified outside of this basin (Garatheríum is based on a species from El Kohol, Algeria). Among the Paleocene-Eocene lineages from the Ouarzazate basin, it should be also mentioned a new possible carnassial form (carnivoran or creodont; Adrar Mgorn 1), and an upper molar of Cimolestes cf. incisus (Adrar Mgorn 1 bis). The upper molar THR 168 previously reported as from an indeterminate didelphodontine is here identified as the M1/ of Afrodon chleuhi. The micromammal faunas from the Ouarzazate basin are positioned in the global chronological framework of the mammal localities from the Paleogene of the Arabo-African domain. 


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Published in Vol. 27, Fasc. 3-4 (1998)

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

doi: 10.18563/pv.39.2.e1
 
  Abstract

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


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Published in Vol.39-2 (2015)

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The evolution of the molar pattern of the Erethizontidae (Rodentia,Hystricognathi) and the validity of Parasteiromys Ameghino, 1904.
Adriana M. Candela
Keywords: Argentina; Erethizontidae; Hystricognathi; Miocene; Molar evolution; Porcupines; Rodentia; Systematics
 
  Abstract

    The genus Parasteiromys AMEGHINO, 1904 is revalidated, and P. friantae sp. nov. (Hystricognathi, Erethizontidae) from Colhuehuapian (early Miocene) sediments of the southern cliff of Colhue-Huapi Lake (Province of Chubut, Argentina), is described. The molar morphology of these taxa and of living porcupines adds new elements to understand the dental evolution of the Erethizontidae, and to propose the hypothetical ancestral molar pattern for this family. This pattern does not correspond to any of the morphologies traditionally proposed as ancestral for South American hystricognathous rodents. The proposed pattern is characterized by a metaloph disconnected from the posteroloph and oriented towards the hypocone, and the third loph incompletely developed with the lingual portion homologous to the mesolophule of Baluchimyinae (Chapattimyidae) from the Miocene of Pakistan. The inferred steps of the molar evolution of erethizontids towards the pentalophodont condition, considered derived for the family, are illustrated. This study strengthens the hypothesis placing erethizontids in a basal position among rodents of the suborder Hystricognathi.

      


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

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Un giraffidae dans le pliocène de Montpellier ?
Claude Guérin
Keywords: Artiodactyla; France; Giraffidae; Mammalia; Montpellier; Ruscinian
 
  Abstract

    An upper giraffid premolar without any indication about its origin is preserved at the Montpellier University among numerous fossils from the ruscinian formation of Montpellier. It can be related to Samotherium, of the Upper Miocene in Eastern Europe, North Africa and Asia, or more probably to Bramatherium  or Hydaspitherium of the Pliocene of South East Asia. The sedimentological study of the matrix shows a calcareous background, which may indicate that this tooth does not come from the Montpellier formation. 


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

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Middle Eocene rodents from the Subathu group, Northwest Himalya.
Kishor Kumar, Rahul Srivastava and Ashok Sahni
Keywords: Chapattimyidae; Eocene; evolution; India; Rodentia; Subathu group; Systematics
 
  Abstract

    Extensive collecting in previously known and new Middle Eocene rodent localities in the Subathu Group of the Rajauri and Reasi districts, Jammu and Kashmir (northwest Himalaya, India) has yielded over 500 isolated cheek teeth, numerous incisors and cheek tooth fragments, and two mandibular fragments with M/1-M/3. An analysis of this additional material and a restudy of that reported earlier from the Metka (Rajauri) area has revealed the presence of diverse Middle Eocene ctenodactyloid rodents in India. The assemblage comprises six genera and twelve species, viz.., Bírbalomys woodi, B. ibrahimshahi, B. sondaari, Basalomys vandermeuleni, B. ijlsti, B. lavocati, Chapattimys wilsoni, C. debruijni, Gumbatomys asifi, cf. Advenimus bohlini, cf. Petrokoslovia sp. indet. 1 and cf. Petrokoslovia sp. indet. 2. Most species of this assemblage are endemic to the Indian subcontinent and are referred to the Family Chapattimyidae. However, at least three taxa, viz.., cf. Advenimus bohlini, cf. Petrokoslovia sp.indet. 1 and cf. Pezrokoslovia sp. indet. 2 show close affinities with their Central and Eastern Asiatic contemporaries and are attributed to the Family Yuomyidae. The dentitions of most of the Middle Eocene rodents from India are described here in better detail thus providing more precise characterization than was available earlier. The taxonomie status of Basalomys, formerly a subgenus of Birbalomys has been raised to that of a genus. Basalomys vandermeuleni is here designated as the type species of Basalomys in place of B. ijlsti. The rodent assemblage from the Subathu Group is specifically similar to that from the coeval Kuldana Formation of Pakistan. The absence of Birbalomys ibrahimshahi and cf. Advenimus bohlini in Pakistan is related to sampling bias. The identifications of the Early Eocene rodents from Barbara Banda, Pakistan have been reexamined and the familial assignments of some of the Early and Middle Eocene rodents from Central and Eastern Asia have been discussed and reviewed in the light of recent discovery of early rodents in Mongolia.

      


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

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

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


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

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Analysis of mammalian communities from the late Eocene and Oligocene of southern France
Serge Legendre
Keywords: Late Eocene; Mammalian communities; Oligocene; Quercy; Southern France
 
  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. 


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

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Un nouveau genre de ?Palaeotheriidae (Perissodactyla, Mammalia) décelé dans les phosphorites du Quercy (Eocène supérieur ou Oligocène) d'après un arrière crâne sans dents.
Jean-Albert Remy
Keywords: endocranial cast; Epitympanic sinus; Palaeotheriidae; Paléogène; Quercy Phosphorites; skull anatomy
 
  Abstract

    A rear skull from the Quercy Phosphorites is described. It documents a new perissodactyl genus, likely assignable to the family Palaeotheriidae and probably paleogene of age. Owing to the lack of any tooth, this family assignment remains however somewhat hypothetical. The specimen is firstly characterised by the presence of a wide epitympanic sinus swelling and hollowing the squamosal shell and the post-glenoid process. This cavity might make up a peculiar pattern of improvement for the hearing apparatus by carrying out a kind of drum near the middle ear, whereas the bony tympanic remains barely bulged and forms but a few developed auditory bulla. This pattern appears an outcome of a trend observed with many palaeotheriids, such as Plagiolophus. Furthermore, the endocranial cast shows a rather high degree of gyrencephaly for a paleogene mammal. The prominent lambdoidal crest points out a powerful nape musculature and a lowered head bearing. Consequently, it is assumed that such an animal was probably living in somewhat open places, at the expense of rather tough vegetables. It might have been accordingly provided with a semi-hypsodont, cement covered, "plagiolophoid" dentition. 


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

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Les gisements de Robiac (Eocène supérieur) et leurs faunes de Mammifères.
Jean Sudre
Keywords: Fauna; Late Eocene; Mammalia; Robiac

doi: 10.18563/pv.2.3.95-156
 
  Abstract

    Designated the type-locality of a late Eocene paleomammal zone, Robiac has recently been the object of important excavations. The first results of the new collecting, as  well as a revision of the material in old collections, are given in this work.
    Two stratigraphic section, cutting through the two sites presently distinguished (Robiac-Nord and Robiac-Sud) reveal the lithologic variation at the base of the Fons Limestone and the localization of three fossiliferous beds at Robiac-Sud.
    The molluscan fauna and the flora (charophytes), which have already been described, as well as that of the lower vertebrates, have been listed.
    A list of 46 mammalian species (only 16 species were known previous to 1964) has been established. The micro-mammals, nearly all new in this fauna (marsupials, insectivores, bats, rodents, primates, and some smallsized artiodactyls), Were obtained only after screen-washing of the matrix; about 4 tons of sediment were thus treated.
    The artiodactyls have been the most extensively analyzed; 6 genera, of which one is new, have been recognized. The latter is described as Robiacina minum n.g., n.sp., and represents a very small artiodactyl of the family Anoplotheriidae. The taxonomie status of certain species formerly described has been clarified by the designation of lectotypes (Cebochoerus robiucensis, Catodonerium robiacense, Xiphodon castrense).
    The paleontologic corrélations at present possible between the late Eocene faunas have allowed the relative positions of te different French localities of this age to be established; the Guépelle locality, it seems, could define in the future a new paleomammal zone.
      


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Published in Vol. 02, Fasc. 3 (1969)

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Revision of the family Cephalomyidae (Rodentia, Caviomorpha) and new cephalomyids from the early Miocene of Patagonia.
Alejandro Kramarz
Keywords: Cephalomyidae; Lower Miocene; Patagonia; Rodentia; Soriamys; Systematics
 
  Abstract

     A new genus of hystricognath rodent with two new species, Soriamys gaimanensis and Soriamys ganganensis, from the Colhuehuapian Age (Early Miocene), Sarmiento Formation, of Patagonia is described. The first species comes from the south barranca of the valley of Rio Chubut, near Gaiman locality (Chubut Province). It is known through a great number of dental remains in different stages of wear. The teeth are protohypsodont, with cement in the principal valleys. P4 are simpler, more oval inoutline and without a differentiated hypocone-hypoflexus. Upper molars are pentalophodont in early stages of wear and become bilobated in middle and advanced stages; M3 have a temporary third posterior lobe due to the maintenance of the braquiflexus on the posterior wall of the tooth. Lower teeth have a completely asymrnetrical pattern in relation to the uppers. The molars are trilophodont, with only one complex crest in the trigonid composed of the fusion of the anterolophid and mesolophid. The dp4 have a derived pentalophodont pattern due to the loss or fusion of the mesolophid and the development of an accessory transverse crest between the anterolophid and metalophid. The second species is known through a complete skull and jaw and other skull fragments with the dentition, proceeding from Pampa de Gan Gan, Chubut province. Respect to the first species, the teeth are higher crowned, with an earlier occlusal simplification and a third posterior lobe of M3 more developed and persistent. The skull and jaws show many chinchilloid characters, such as jugal bone with an ascending process, concave palate, very prominent dorsal shelf of the masseteric fossa, nasolachrymal duct opened laterally on the maxillary and very developed lateral mandibular fossa. Moreover, Soriamys is closely related to Cephalomys by sharing a similar asymmetric dental pattern and other dental and mandibular characters. These two genera constitute a natural group, the Cephalomyidae, with peculiar dental characters, like the asymmetric pattem of the upper and lower teeth; Cephalomyopsis, and probably Litadontomys, can be considered part of this group. Scotamys and Perimys constitute a distinct lineage (the Neopiblemidae or Perimyidae), more closely related to the chinchillids. Many characters shared by cephalomyids, eocardiids and caviids suggest a closer affinity between the Chinchilloidea and the Cavioiidea as a whole. Abrocoma shows also an asymmetric dental pattern and other chinchilloid features that suggest some degree of relationship with the cephalomyids, still not well determined. 


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Published in Vol. 30, Fasc. 1-2 (2001)

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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
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. 


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

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Rythme et modalités de l'évolution chez les rongeurs à la fin de l'Oligocène-leurs relations avec les changements de l'environnement.
Bernard Comte
Keywords: Environment; evolution; Oligocene; Rodents; Systematics
 
  Abstract

    The analysis of oxygene isotope variations as well as paleobotanical data suggest that the Oligocene/Miocene boundary corresponds to a transitional period marked by floristical and climatic variations. During this period, the pyreneo-alpine tectonics has contribued to modify the geography and western Europe landscapes. Faunal changes (appearances, extinctions, migrations) are observed in different mammalian groups, notably in the rodents. A study of the evolutionary trends and patterns in paleogene rodents is involved for the period ranging from level MP 28 of the Late Oligocene to the Early Miocene, including the Oligo-Miocene boundary.
    The Rodents fauna from the sites of Venelles (Bouches-du-Rhône District, France) and Thezels (Lot, France), previously mentionned in litterature, have been studied. The first description of the Eomyidae of La Milloque (MP 29) has been completed. These faunas are compared to those from various localities dating from the considered period. In La Milloque, a new representative of the Eomys species is described next to a form close to Rhodanomys hugueneyae ENGESSER, 1987. It is the Eomys milloquensis nov. sp., the likely descendant of Eomys quercyi COMTE & VIANEY-LIAUD, 1987. Two new species are also described in Thezels: Eucricetodon thezelensis nov. sp., resulting from a likely and local evolution of Eucricetodon praecursor (SCHAUB, 1925) from La Milloque, which, in the same geographic area, could be at the origin of Eucricetodon hesperius ENGESSER, 1985 from Paulhiac. Plesiosminthus admyarion nov. sp., quite distinct from Plesiosminthus schaubi VIRET, 1926, which announces Plesiosminthus myarion SCHAUB 1930. Venelles 'Plesiosminthus schaubi population is considered as a sub-species, named Plesiosminthus schaubi meridionalis nov. subsp. New phylogenetic patterns are proposed. Among the Eomyidae, a quantification of various features of the M1-2/ crown (hypsodonty, degree of abrasion, occlusal angle, state of development of the I and V anticlines), and a comparison with the occlusal diagram of the other teeth among various other populations allows a more efficient separation of Eomys and Rhodanomys genera. In Western Europe, and within this period, it finally does not seem possible to gradually connect the genus Eomys to the genus Rhodanomys. The evolution of the Eomys quercyi - milloquensis lineage seems to underline a similar evolution to that which may have led from the Eomys to the Rhodanomys form. The latter which appears totally accomplished at level MP 29 of the Oligocene is considered as an immigrant. If we compare the most representative species of the Venelles, Thezels, and Coderet sites, (i.e. Rhodanomys, Eucricetodon, Adelomyarion, Peridyromys, Plesíosminthus), it becomes impossible to confirm their biochronological separation. The noticeable differences between the populations may be interpreted as geographical variations. An explanation to these variations, and to fauna's evolution during the Late Oligocene and Early Miocene can be found in the environmental modifications, supported by isotopic, paleobotanical and sedimentologic analysis. A tentative reconstruction of the environments is attempted by the cenogram method. The analysis of the fluctuations of fauna's diversity shows variations which may be correlated to a drop in temperature at MP 29, during the Late Oligocene, followed by an increase in temperature along with an aridity phenomenom, during the basal Miocene (MN O).The confrontation of various methods give the opportunity of reconstituting and comparing the evolution of the environment of three sequences of sites chosen from different regions. Ecological affinities of various rodents' species are being examined. It is possible to consider that the integration of all the conclusions resulting from this study should lead to an explanation to the evolution of rodents for the period around the Oligocene-Miocene boundary. The site of Coderet- level 3- would be posterior to the latter, at the beginnig of the Miocene, and would mark the level MN 0 of the Aquitanian.

      


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Published in Vol. 29, Fasc. 2-4 (2000)

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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
Keywords: Eocene; Quercy Phosphorites
 
  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. 


  Article infos

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

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Additions to the elasmobranch assemblage from the Bandah Formation (middle Eocene, Bartonian), Jaisalmer District, Rajasthan, India, and the palaeobiogeographic implications of the fauna
Rajendra S. Rana, Raman Patel, David J. Cicimurri and Jun A. Ebersole
Keywords: Chondrichthyes; Elasmobranchii; Indian Ocean; Palaeogene; South Asia

doi: 10.18563/pv.44.2.e1
 
  Abstract

    Isolated elasmobranch teeth (sharks and rays) from the middle Eocene (Bartonian) Bandah Formation in the Jaisalmer District of Rajasthan, India are described. The remains improve our knowledge of the environment represented by this lithostratigraphic unit and the ecology preserved therein. Seventeen unequivocal taxa were identified, including Nebrius sp., Striatolamia aff. S. macrota, Brachycarcharias atlasi, B. lerichei, cf. Jaekelotodus sp., Carcharhinus mancinae, Rhizoprionodon sp., Physogaleus sp., Galeocerdo clarkensis, G. eaglesomei, Odontorhytis aff. O. pappenheimi, “Rhinobatos” sp., “Dasyatis” sp., Coupatezia sp., “Aetomylaeus” sp., “Rhinoptera” sp., and Ouledia aff. O. lacuna. Of these, “Aetomylaeus” sp., B. atlasi, C. mancinae, G. clarkensis, G. eaglesomei, cf. Jaekelotodus sp., Nebrius sp., Odontorhytis aff. O. pappenheimi, Ouledia aff. O. lacuna, and “Rhinoptera” sp. are reported from the middle Eocene of India for the first time. The Bandah Formation elasmobranch palaeofauna has close affinities to the Palaeocene-Eocene Tethyan/Paratethyan faunas of Africa, Madagascar, Asia, and Europe, and some taxa indicate a western hemisphere influence from North America. The Bandah Formation palaeofauna indicates that deposition occurred in a moderately shallow marine environment. The Bartonian age is primarily based on foraminifera but is corroborated by the presence of elasmobranch taxa that also occur in contemporaneous deposits elsewhere. The marine regression started during the early Palaeogene, and our study indicates that the sea completely withdrew from the Jaisalmer Basin after the deposition of the Bandah Formation. This event may have been synchronous with the middle Eocene uplift of the Himalayan-Tibetan Plateau. 


  Article infos

Published in 44-2 (2021)

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La poche à phosphate de Ste-Néboule (Lot) et sa faune de vertebres du Ludien supérieur. 7- Didelphides (Marsupiaux)
Jean-Yves Crochet
Keywords: Eocene; Quercy Phosphorites
 
  Abstract

    The family Didelphidae is represented by three species in the Sainte-Néboule site, phosphorites of Quercy (lower Oligocene, San Cugat's nivel): Amphiperatherium minutum (Aymard), Amphiperatherium sp. and Peratherium cuvieri (Fischer). Only the first  and  third species are abundant (88 and 97 pieces). This two populations are described. The marsupial fauna of the european lower Oligocene is not recognized in its entirety in this site. 


  Article infos

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

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