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New late Paleocene rodents (Mammalia) from Big Multi Quarry, Washakie Basin,Wyoming.
Mary R. Dawson and Christopher K. Beard
Keywords: Clarkforkian; North America; Paleocene; Rodentia
 
  Abstract

    The earliest North American rodents occur in basal Clarkforkian beds of the Fort Union Formation at Big Multi Quarry near Bitter Creek, northern Washakie Basin, Sweetwater County, Wyoming, and in closely correlative Fort Union beds formerly accessible in the Eagle Coal Mine near Bear Creek, northern Clark's Fork Basin, Carbon County, Montana. Two new species of early Clarkforkian rodents, Paramys adamus and Alagomys russelli, are described from Big Multi Quarry. Paramys adamus is represented by virtually complete upper and lower dentitions, which demonstrate that this species is one of the most primitive North American paramyids yet discovered. These specimens form the basis for a reevaluation of the content and stratigraphic range of P. atavus, which is known with certainty only from Bear Creek. Alagomys russelli is the first North American record for the enigmatic rodent family Alagomyidae, otherwise known from ?late Paleocene-early Eocene localities in Mongolia and China. Phylogenetic analysis of dental and gnathic traits suggests that Alagomyidae form the sister group of all other undoubted rodents. At least two rodent clades, alagomyids and basal paramyids, seem to have invaded North America from Asia at the beginning of Clarkforkian time, but only the paramyids persisted to undergo a significant evolutionary radiation in North America. 


  Article infos

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

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Les Gliridés (Rodentia) de l'Oligocène supérieur de Saint-Victor-la-Coste (Gard).
Marguerite Hugueney
Keywords: Gliridae; Late Oligocene

doi: 10.18563/pv.2.1.1-16
 
  Abstract

    The locality of St.-Victor-la-Coste (Gard) has yielded, rather abundantly, teeth of two glirids hitherto very poorly known: Glirudinus praemurinus (Freudenberg) and Glirudinus glirulus (DEHM). It has permitted, moreover, new views on the evolution of Peridyromys murinus (POMEL). Study of these forms confirms the late Oligocene age of the fauna, without allowing, however, further precision. 


  Article infos

Published in Vol. 02, Fasc. 1 (1968)

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Autopsie d’une radiation adaptative : Phylogénie des Theridomorpha, rongeurs endémiques du Paléogène d’Europe - histoire, dynamique évolutive et intérêt biochronologique
Monique Vianey-Liaud and Laurent Marivaux
Keywords: Diversification; Extinction; Paléoenvironnements; Rodentia; Theridomyoidea

doi: 10.18563/pv.40.3.e1
 
  Abstract

    Résumé :
    L’étude des rongeurs Theridomorpha permet de suivre le déroulement d’une radiation adaptative pendant toute sa durée (Eocène moyen-Oligocène terminal), sur un territoire restreint à l’extrémité ouest de l’Europe Occidentale. Dans ce papier, la phylogénie de ce groupe est établie à partir d’une analyse cladistique reposant sur l’examen de 315 caractères (310 dentaires). Le groupe d’intérêt comprend 110 des 132 espèces (24 genres) de Theridomyoidea et deux genres encore inclus jusqu’ici dans les Reithroparamyinae qui rejoignent les Theridomorpha. Les groupes externes comprennent des Glires basaux, Cocomys, Tanquammys et 16 Ischyromyiformes. Un cadre phylogénétique robuste est produit, qui permet de clarifier la systématique des Theridomorpha. La position des Remyoidea (nov. sup.fam.) au sein des Ischyromyiformes, extérieure aux Theridomorpha, est confortée. Les Protadelomys et Tardenomys sont à la base des Theridomyoidea, avant la séparation en deux clades correspondant aux familles Pseudosciuridae et Theridomyidae. Les sous-familles sont consolidées : Pseudosciurinae et Sciuroidinae pour les Pseudosciuridae ; Issiodoromyinae, Oltinomyinae, Columbomyinae, Theridomyinae, auxquelles s’ajoute au moins une nouvelle sous-famille (Patriotheridomyinae), pour les Theridomyidae. La topologie des chrono-espèces (sensu Simpson), traitées antérieurement comme lignées évolutives, apparaît dans la plupart des cas sous forme de clades successifs dans lesquels les espèces sont le plus souvent arrangées de manière pectinée, émergeant dans l’ordre stratigraphique. L’analyse des caractères aux principaux nœuds permet de consolider les caractères diagnostiques des taxons et les tendances évolutives, ainsi que de discuter des divers parallélismes et convergences dans l’évolution des structures et patrons dentaires (e.g., émail des incisives unisérié chez les Issiodoromyinae et les Patriotheridomyinae, ou pseudo-multisérié chez les Blainvillimys les plus hypsodontes, les Protechimys et Archaeomys ; patrons dentaires téniodontes ; allongement des dents déciduales chez les Patriotheridomyinae, Issiodoromyinae et Theridomyidae ; sélénodontie ou lophodontie). Les dynamiques évolutives traduites par les changements morphologiques sont mises en relation avec les variations environnementales. Enfin, les implications biochronologiques de l’évolution des Theridomyoidea sont discutées.
    Abstract:
    The adaptive radiation of the rodents Theridomorpha occurred during a limited time window (middle Eocene to late Oligocene), on an area restricted to Western Europe. In this paper, the phylogeny of this group is established via a cladistic assessment of 315 morphological characters (310 dental). The group of interest encompasses 110 upon 132 species (24 genera) of Theridomyoidea, and two genera formerly included within the Reithroparamyinae, and which are included here within the Theridomorpha. The outgroups include basal Glires, Cocomys, Tanquammys and 16 Ischyromyiformes. A robust phylogenetic frame is produced, which allows clarifying the systematics of the Theridomorpha. Within the Ischyromyiformes, the Remyoidea (nov. supfam.) are set apart from the Theridomorpha. Protadelomys and Tardenomys represent the earliest offshoots of the Theridomyoidea, before the dichotomy between Pseudosciuridae and Theridomyidae. It supports the former subfamilies Pseudosciurinae and Sciuroidinae within the Pseudosciuridae; and for the Theridomyidae: the Issiodoromyinae, Oltinomyinae, Columbomyinae, Theridomyinae, with at least one new subfamily (Patriotheridomyinae). The topologies of the chronospecies (sensu Simpson), formerly considered as evolutionary lineages, appear in most cases as successive clades, in which the species are generally pectinately arranged and emerging in the stratigraphic order. The analysis of characters supporting the main nodes allow consolidating the diagnosic characters of the taxa and their evolutionary trends, as well as discussing the various cases of parallelism and convergence in the evolution of structures and dental patterns (e.g., uniserial incisor enamel for Issiodoromyinae and Patriotheridomyinae, or pseudo-multiserial for the most hypsodont Blainvillimys, Protechimys and Archaeomys; taeniodont dental patterns; lengthening of deciduous premolars for Patriotheridomyinae, Issiodoromyinae and Theridomyidae; selenodonty or lophodonty).
    Evolutionary dynamics are analysed with respect to environmental changes. Finally, biochronological implications of the evolution of Theridomyoidea are discussed.
      


  Article infos

Published in Vol 40-3 (2017)

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S.I. Data
Systematic and evolutionary relationships of the hipparionine horses from Maragheh, Iran (Late Miocene, Turolian age)
Raymond L. Bernor
Keywords: evolution; Hipparionine horses; Iran; systematics; Turolian
 
  Abstract

    A systematic analysis of an hipparionine horse assemblage from Maragheh, Iran is made. A brief orientation to systematic philosophy and informal superspecific characterizations of some Old World hipparionines is given as a background to this work. A character state analysis of skulls is made, and has revealed five distinct species. A character state and stratigraphic trend analysis of isolated check tooth and postcranial remains, with known provenance, is also made. These two combined analyses reveal that the most resolute discrimination of hipparionine species and their evolutionary relationships occurs when multiple character complexes of associated skulls, maxillary and mandibular dentitions are made. When this is not possible, skulls have provided the best basis for discriminating species and their evolutionary relationships. Traditional characters of isolated cheek teeth and postcranial remains are shown here to offer limited information content for hipparionine phylogenetic systematics. The systematic portion of this study includes a comprehensive description of cranial and postcranial remains, and has further corroborated the distinction of five species which belong to at least three superspecific groups including: «Hipparion» geltyi sp. nov., Group 1; Hipparion prostylum (s. l.), and Hipparion campbelli sp. nov., Group 3; «Hipparíon» aff. moldavicum and «Hipparion» ?matthewi, Group 2. These species stratigraphic ranges and evolutionary relationships are also given here and argued to be important for establishing future hipparionine geochronologic correlations between a number of Eurasian late Miocene provinces. 


  Article infos

Published in Vol. 15, Fasc. 4 (1985)

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Fossil mammals and the age of the changxindian formation, Northeastern China
Spencer G. Lucas
Keywords: Changxindian Formation; China; Eocene; Fossil mammals
 
  Abstract

    Re-evaluation of the small collection of mammal fossils from the Changxindian Formation near Beijing, China indicates the following taxa are present: Eutheria, Hypsimilus beifingensis, cf. Miacis sp., Anthracotheriidae and Forstercooperia grandis. The presence of Forstercooperia grandis indicates an Irdinmanhan age and does not support previous assignment of a Sharamurunian age to the Changxindian Formation. 


  Article infos

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

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A mandible of the hyracoid mammal Titanohyrax andrewsi in the collections of the Muséum National d'Histoire Naturelle, Paris (France) with a reassessment of the species
Rodolphe Tabuce
Keywords: Afro-Arabia; Fayum; Oligocene; Titanohyracidae

doi: 10.18563/pv.40.1.e4
 
  Abstract

    An unpublished mandible of the large hyracoid Titanohyrax andrewsi from the early Oligocene Jebel Qatrani Formation, Fayum Depression, Egypt is described. This specimen has a twofold importance. Firstly, it opens an unexpected window on early paleontological research in the Fayum because it was discovered as early as 1904 by the French paleontologist René Fourtau during an expedition to the Fayum organized by the Muséum National d’Histoire Naturelle, Paris (MNHN). This expedition has remarkably never been mentioned in the literature. Secondly, the mandible documents the best-preserved specimen of T. andrewsi, permitting a revision of one of the very rare Paleogene hyracoids. Interestingly, the new mandible was discovered two years before the first report of the species by Charles W. Andrews. The hypodigm of T. andrewsi is reviewed and the dentition as a whole is compared in detail, notably with other Titanohyrax species from the Fayum. The validity of the large Titanohyrax schlosseri” species is discussed, but a pronounced sexual size dimorphism for T. andrewsi is favoured. 


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Published in Vol.40-1 (2016)

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A survey of Cretaceous tribosphenic mammals from middle Asia (Uzbekistan, Kazakhstan and Tajikistan), of their geological setting, age and faunal environment
Lev A. Nessov, Denise Sigogneau-Russell and Donald E. Russell
Keywords: Cretaceous; Environment; Middle Asia; Sharks; Tribosphenic mammals
 
  Abstract

    This paper is an English concentrate of various Russian publications by the senior author presenting the mammaIian taxa from the Cretaceous (Albian through Santonian) of the region termed Middle Asia by Soviet geographers. The diagnoses are the unmodified, literal translation of the original version, but are followed with short complementary remarks; most of the species are illuslrated anew with SEM photographs, others are by normal photography. The fossiliferous formations are cited and arguments for their dating are given. Finally, the main vertebrate groups accompanying mammaIs are listed and the environment and climate at the time of deposition are suggested. In conclusion, an hypothesis on the origin and high diversity of tribosphenic mammals on the Cretaceous coastal plains of southwest Asia is proposed. In appendix the taxon Khuduklestes bohlini novo gen. novo sp. is formally defined. 


  Article infos

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

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Une faune du niveau d'Egerkinger (MP 14; Bartonien inférieur) dans les phosphorites du Quercy (Sud de la France)
Jean Sudre, Bernard Sigé, Jean-Albert Remy, Bernard Marandat, Jean-Louis Hartenberger, Marc Godinot and Jean-Yves Crochet
Keywords: Biochronology; Early Bartonian; Eocene; evolution; Mammals; New taxa; Quercy
 
  Abstract

    The Laprade fauna is chronologically situated between those from Egerkingen and Lissieu and consequently, is close to the MP 14 reference-level of the European mammalian biochronological scale (Symposium of Mainz, 1987).
    This new fauna is presently the oldest known in the Quercy phosphorites, formerly the Le Bretou fauna (MP 16) was considered as the oldest one. The Laprade fauna includes 21 species which belong in 7 mammalian orders (Marsupialia: Amphiperatherium bastbergense, Amphiperatherium goethei; Apatotheria: Heterohyus (Gervaisyus) pygmaeus nov. subgen., nov. sp.; Lipotyphla: Saturninia cf. mamertensis, Saturninia cf. intermedia; Chiroptera: Vespertiliavus lapradei nov. sp.; Rodentia: Protadelomys cf. lugdunensis, Elfomys nov. sp.; Primates: Nannopithex cf. filholi, cf. Pseudoloris or Pivetonia; Perissodactyla: ?Palaeotherium ?castrense, small-sized Palaeotherium sp., Plagiolophus sp., Anchilophus sp.; Artiodactyla: Dichobune cf. robertiana, Mouillacitherium cartieri, Tapirulus cf. depereti, Mixtotherium priscum, Pseudamphimeryx schlosseri, and Artiodactyla indet). Sixteen of these species are mentioned for the first time from the Quercy faunas.
    The recognition of a new apatemyid, Heterohyus (Gervaisyus) pygmaeus nov. subgen., nov. sp., attests to an early origin of a lineage known in the Late Eocene. The emballonurid bat Vespertiliavus lapradei nov. sp. is presently the earliest record of this genus and family. This Auversian fauna leads to discuss the age of taxa showing archaic features. These taxa were defined on specimens collected in the Quercy during the last century and have never been found in the Quercy localities recently investigated. This fauna bears also evidence of a karstic filling episode older than those previously dated by fossils in the Quercy Jurassic. 


  Article infos

Published in Vol. 20, Fasc. 1 (1990)

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Relations phylétiques de Bachitherium filhol, ruminant de l'Oligocène d'Europe Occidentale.
Denis Geraads, Geneviève Bouvrain and Jean Sudre
Keywords: Artiodactyla; Bachitherium; Cladistic analysis; France; Mammalia; Oligocene; Ruminantia
 
  Abstract

    A detailed comparative study of a complete skeleton of Bachitherium and a cladistic analysis of the sub-order Neoselenodontia lead us to propose a cladogram and a new classification of this group. The Tylopoda are the sister-group of the Ruminantia, which are chiefly defined by the fusion of the cuboid and navicular. Within this infra-order, Amphimeryx is the sister genus of a tetraselenodont group, in which the Hypertragulidae are well-separated group from a monophyletic group defined by the loss of trapezium, fusion of capitatum and trapezoid, and the isolation of the hypoconid on lower molars. The most primitive genera of this group, Lophiomeryx and Iberomeryx still have an open trigonid on the lower molars, but this is lingually closed in Archaeomeryx, sister-genus of the higher Ruminantia which have fused metatarsals and more evolved milk teeth. We divide them into two pan/orders : Tragulina (including the recent and miocene Tragulidae, and the North-American Leptomerycidae), and Pecora, with reduced lateral metacarpals and a new crest (telocristid) on the lower premolars. Within the Pecora, the upper molars of Gelocus are more primitive than those of Bachitherium (a genus with many autapomorphies in the dentition) itself more primitive than the group Prodremotherium + Eupecora, with fused metacarpals. We consider the Eupecora (including several genera without frontal appendages) to be monophyletic. 


  Article infos

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

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Les Amphibiens et les reptiles du Pliocène supérieur de Balaruc II (Herault, France)
Salvador Bailon
Keywords: Amphibians; Europe; France; Pliocene; Reptiles
 
  Abstract

    The late Pliocene site (MN 16) of Balaruc II (Hérault, France) has provided remains of the following amphibians and reptiles: Chelotriton pliocenicus nov. sp. and Triturus marmoratus (Salamandridae), cf. Rana (Ranidae), cf. Blanus (Amphisbaenidae), cf. Agama (Agamidae),  Gekkonidae indet., Lacerta s.l. (Lacertidae), "Ophisaurus" sp. (Anguidae), Michauxophis occitanus (Aniliidae), Erycinae indet. (Boidae), Elaphe cf. E. longissima and Malpolon sp. (Colubridae), cf. Naja (Elapidae) and Vipera sp. (Viperidae). The salamandrid Chelotriton pliocenicus and the aniliid Michauxophis occitanus constitute, up to now, the only records of these groups in the European Pliocene. The fauna is indicative of a warm, dry
    subtropical climate. 


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Published in Vol. 19, Fasc. 1 (1989)

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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. 


  Article infos

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

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Archosauriform teeth from the upper Triassic of Saint Nicolas-de-Port (Northeastern France).
Pascal Godefroit and Gilles Cuny
Keywords: Archosauriforms; Graoullyodon hacheti; Saint-Nicolas-de-port; Teeth; Upper Triassic
 
  Abstract

    The Late Triassic locality of Saint-Nicolas-de-Port (Meurthe-et-Moselle, France) has yielded numerous isolated teeth belonging to archosauriform reptiles. The following tooth groups can be identified: heterodont phytosaurs, the pterosaur Eudimorphodon, the prosauropod dinosaur Plateosaurus, three types of putative ornithischian teeth and 13 types of carnivorous Archosauriformes indet. Apparent venom-conducting teeth belonging to a new taxon of ?Archosauriformes (Graoullyodon hacheti nov. gen. nov. sp.) are also described. From a palaeogeographical point of view, the ornithischian teeth from Saint-Nicolas-de-Port (if their attribution is confirmed) are the oldest fossils of this group in Europe. The biostratigraphic distribution of the tooth forms mostly suggests a Late Norian or Early Rhaetian (depending on current interpretations) age of the deposits, but do not provide more precisions than fossils previously described from the area. The dietary habits and, consequently, the palaeoecological relationships of the different vertebrate groups discovered at Saint-Nicolas-de-Port are tentatively established: the ornithischian and prosauropod teeth reflect a herbivorous diet, whereas the other archosauriform teeth are probably from camivores or omnivores.

      


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

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Rana (Amphibia : Ranidae) from the upper eocene (MP17a) Hordle Cliff locality, Hampshire, England.
Alan J. Holman and David L. Harrison
Keywords: Amphibia; England; Rana; Ranidae; Upper Eocene
 
  Abstract

    An ilium from the Upper Eocene (MP l7a) of Hordle, England, represents the first report of Rana from the Eocene of Britain. The ilium is similar to those of the water frog (Rana [ridibunda]) species group. 


  Article infos

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

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Les artiodactyles du gisement yprésien terminal de Premontre (Aisne, France)
Jean Sudre and Jorg Erfurt
Keywords: Artiodactyls; France; Mammals; new species; Ypresian
 
  Abstract

    The artiodactyls (Mammalia) from the latest Ypresian locality of Prémontré from the Paris Basin (niveau repère MP 10 in the lower Eocene of the Paris Basin) are described in this paper. Three species have been identified: 1) Diacodexis cf. varleti SUDRE et al., 1983; 2) a new species of Eurodexis ERFURT & SUDRE (E. russelli nov. sp.) defined after the revision of the species Messelobunodon? ceciliensis from the Lutetian beds of Geiseltal (Germany); and 3) Eurodexeinae indet., a probable ancestor of another form from the Geiseltal which was previously recorded as Homacodon? sp. (Erfurt 1993) and now named Parahexacodus germanicus. The two later forms are referred to the new subfamily Eurodexeinae (Erfurt & Sudre 1996). The analysis of these forms as weIl as comparative studies have led us to reconsider our previous conclusions regarding the content of the species Protodichobune oweni LEMOINE 1878 and some aspects of Ypresian diacodexid evolution. One can postulate that the divergence of E. russelli nov. sp. occurred during the first radiation of these primitive artiodactyls. Some other stem form with bunodont teeth such as Protodichobune and Aumelasia have also differentiated from Diacodexis. Like Eurodexis, these two genera persist during the middle Eocene. The absence of Protodichobune and Aumelasia at Prémontré is probably due to particular ecological conditions. 


  Article infos

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

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New remains of the very small cuckoo, Chambicuculus pusillus (Aves, Cuculiformes, Cuculidae) from the late Early/early Middle Eocene of Djebel Chambi, Tunisia
Cécile Mourer-Chauviré, El M. Essid, Hayet Khayati Ammar, Laurent Marivaux, Wissem Marzougui, Rim Temani, Monique Vianey-Liaud and Rodolphe Tabuce
Keywords: Cuckoos; Eocene; Fossil bird

doi: 10.18563/pv.40.1.e2
 
  Abstract

    Abstract: A very tiny cuckoo, Chambicuculus pusillus, was recently described after a few fragments of tarsometatarsi from the late Early/early Middle Eocene of Djebel Chambi, Tunisia. New remains, notably a coracoid, confirm the attribution of this genus to the recent family Cuculidae. This coracoid shows a very elongate and strap-like processus procoracoideus. This morphological feature is otherwise only known in the family Cuculidae. The characteristics of the coracoid and tarsometatarsi show that Chambicuculus is morphologically more advanced over the other stem cuculids described in Europe and North America. Chambicuculus is the oldest Cuculidae known so far. 


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Published in Vol.40-1 (2016)

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Lower Paleogene crocodilians from Silveirinha, Portugal.
Miguel T. Antunes
Keywords: ?Upper Paleocene / Lowermost Eocene; Crocodilians; Ecology; Portugal
 
  Abstract

    The presence at Silveirinha of one of the earliest, ? Late Paleocene or Lowermost Eocene, european representatives of the genus Diplocynodon is based mostly on isolated bones and teeth (often from juveniles). This small-sized form is the only crocodilian so far recognized in this site. The longevity of Diplocynodon in Portugal becomes much extended; the genus survived there until the Middle Miocene at least. A discussion on the possible affinities with other eocene Díplocynodon and especially those from Cubillos-Valdegallina (Zamora, Spain) is presented. On the other hand, differences have been detected in comparison with: Díplocynodon tormis, from the middle Eocene of the Douro basin in Spain, which may belong to another phyletic line; and the aff. Diplocynodon from Dormaal (Belgium) and Le Quesnoy (France), nearly contemporaneous of Silveirinha. The Silveirinha Diplocynodon and many other data strongly suggest moist, subtropical, quite limited in space environments related to an alluvial plain crossed by small, meandering channels. 


  Article infos

Published in Vol. 32, Fasc. 1 (2003)

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The endocranial cast and encephalization quotient of Ptilodus (Multituberculata, Mammalia)
David W. Krause and Zofia Kielan-Jaworowska
Keywords: encephaIization quotient; endocranial cast; Montana; Multituberculata; olfactory bulbs; Paleocene; Ptilodus
 
  Abstract

    Simpson (1937a) reconstructed the brain of the Paleocene multituberculate Ptilodus as having the olfactory bulbs widest anteriorly, an unusual condition among mammals. Slight preparation and reexamination of the endocast specimens of Ptilodus reveals that the olfactory bulbs in fact taper anteriorly, as in the recently-described endocranial casts of three multituberculate species from the Late Cretaceous of Asia, and as in those of other mammals. The brain of Ptilodus was therefore essentially of the same general pattem as in other multituberculates. Ptilodus differs, however, in having the vermis more deeply inserted between the cerebral hemispheres. Other details concerning the endocast morphology of Ptilodus are clarified.

    The encephalization quotient (EQ) of Ptilodus is recalculated from revised estimates of both endocranial volume and body mass to fall somewhere within a broad range of values; from 0.41 to 0.62 if the olfactory bulbs are included and from 0.37 to 0.55 if they are not. In any case, the relative brain size of Ptilodus is roughly equivalent to that of Chulsanbaatar, the only other multituberculate for which EQ has been calculated, but considerably smaller than that of an average extant mammnal. 


  Article infos

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

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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. 


  Article infos

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

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Functional aspects of the evolution of rodent molars
Percy M. Butler
Keywords: Chewing; Muridae; Rodents; Wear facets
 
  Abstract

    The wear facets of primitive rodents can be homologized with those of primitive primates and ungulates. As in primates, the jaw movement was ectental, with an increased anterior component in the lingual phase (phase ll). The buccal phase (phase I) in rodents approaches the horizontal and it tends to be reduced in importance in comparison with the lingual phase. ln more advanced rodents the efficiency of grinding is increased by the development of additional cutting edges of enamel (e.g. enlargement of hypocone, development of mesoloph and lingual sinus). The buccal phase movement becomes lined up with the lingual phase movement to form a single oblique chewing stroke,resulting in planation of the crown. As the stroke becomes more longitudinal (propalinal) the enamel edges become more transverse. In Muridae propalinal chewing evolved before the loss of cusps, facets were reorientated and additional cusps developed. 


  Article infos

Published in Vol. 9, Ext (1980)

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Artiodactyla from the early Eocene of Kyrgyzstan
Alexander Averianov
Keywords: Artiodactyla; Asia; Diacodexeidae; Eocene; Kyrgyzstan
 
  Abstract

    Isolated upper cheek teeth of the primitive artiodactyl Diacodexis sp., upper molars of Eolantianius russelli gen. et sp. nov. (Diacodexeidae), two lower molars tentatively referred to Eolantianius russelli gen. et sp. nov., and astragali of Diacodexeidae indet. are described from the early Eocene (late Ypresian) of locality Andarak 2 in Kyrgyzstan. 


  Article infos

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

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