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Comparative bone histology of rhabdodontid dinosaurs
Edina Prondvai Logo
Published online: 17/11/2014

Keywords: bone histology-based ontogeny; Mochlodon; Rhabdodon; skeletal maturation; Zalmoxes

https://doi.org/10.18563/pv.38.2.e1

  Abstract

    A comparative bone histological study of the three known genera of the endemic European ornithopod dinosaur family, Rhabdodontidae, is presented here in an ontogenetic context. Investigated specimens were assigned to different ontogenetic stages based exclusively on the histological indicators of osteologic maturation during diametrical bone growth; an entirely size-independent method as opposed to most previous studies. Qualitative comparison of bone histology of corresponding ontogenetic stages and elements among the three valid rhabdodontid genera, Mochlodon, Zalmoxes, and Rhabdodon, revealed some consistent patterns. Genus specific histological differences within Rhabdodontidae are most expressed between Rhabdodon and the Mochlodon-Zalmoxes clade. These indicate a prolonged phase of fast growth and a less constrained cyclicity in the growth dynamics of Rhabdodon, as opposed to the slower and more regulated growth strategy reflected in the bones of Mochlodon and Zalmoxes. These genus specific differences are consistent with the phylogenetic interrelation of the genera and are most probably related to the pronounced differences in body size. However, when compared to other ornithopods, most detected histological features in rhabdodontids do not seem to reliably reflect either phylogenetic relations or body size. A notable common feature of all rhabdodontid genera irrespective of body size is the ontogenetically early onset of cyclical growth and secondary remodelling; a pattern that more resembles the condition found in derived ornithopods than that described in more basal taxa which are closer relatives of rhabdodontids. The recognition of taxon-specific histological patterns as well as patterns indicative of ecological and thereby functional traits clearly requires more accurate, preferably quantitative evaluations.   


  PV article infos

Published in Vol.38-2 (2014)

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A new study of the anthracotheres (Mammalia, Artiodactyla) from pondaung formation, Myanmar: systematics implications
Aung N. Soe
Published online: 16/12/2008

Keywords: Anthracohyus; Anthracokeryx; Anthracotherium; Pondaung Formation; sexual dimorphism; Siamotherium; South East Asia; taxonomy

https://doi.org/10.18563/pv.36.1-4.89-157

  Abstract

    Anthracotheres from the Pondaung Formation, Myanmar, are considered as one of the most primitive artiodactyl groups and they represent the oldest known record in the world. Thus, the understanding of this group has numerous implications for evolutionary biology and biochronological correlations. However, the systematlcs of these mammals has been interpreted in different ways, and the main debate focuses on the number of taxa represented in the Pondaung Formation. The revised taxonomy proposed here is mainly based on the relative development of the upper molar W-shaped ectoloph, system of crests and stylar cusps, and on body size. On the basis of these characters, they are classified into four genera including six different species. Two well-known genera, Anthracotherium and Anthracokeryx, are validated and more precisely diagnosed. Anthracokeryx possesses a better developed W-shaped ectoloph, system of crests and stylar cusps than Anthracotherium, which displays notable differences with the more derived representatives of this genus. Both of these Pondaung genera show evidence for sexual dimorphism. However, the incompleteness of fossil material fueled a debate concerning the status of two additional Pondaung anthracotheres, Siamotherium and Anthracohyus. The latter genus is of uncertain affinities, but it has been considered as a hippopotamid ancestor. Despite new material attributed to these two forms, additional discoveries are still required to establish their taxonomic status. The hypothesis that Southeast Asia was the centre of origin of Anthracotheriidae is supported by the retention of numerous primitive dental characters in these taxa and by the antiquity of the Pondaung Formation, to which an age of 37 My is now generally accepted. 


  PV article infos

Published in Vol. 36, Fasc. 1-4 (2008)

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Henri Menu, 1925-2007
Bernard Sigé
Published online: 16/12/2008

Keywords: bats; biography

https://doi.org/10.18563/pv.36.1-4.1-5

  Abstract

    Record of life and works of Henri Menu, French zoologist, contributor to the knowledge of living and fossil bats. 


  PV article infos

Published in Vol. 36, Fasc. 1-4 (2008)

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Critical comments on the genus Propachynolophus Lemoine, 1891 (Mammalia, Perissodactyla, Equoidea)
 
Jean-Albert Remy
Published online: 27/09/2017

Keywords: Eocene; Eurohippus; Pachynolophus; Propalaeotherium; tooth morphology

https://doi.org/10.18563/pv.41.1.e3

  Abstract

    Abstract
     The validity of Propachynolophus Lemoine, 1891, supposedly an intermediate between Hyracotherium Owen, 1841 and Pachynolophus Pomel, 1847, has been questioned for a long time. A detailed analysis of features on which this genus is based further supported by a formal cladistic analysis demonstrates that Propachynolophus is not a valid taxon. The type species, “Propachynolophus gaudryi Lemoine, 1891” shall be assigned to Propalaeotherium Gervais, 1849, under the new combination Propalaeotherium gaudryi (Lemoine, 1891). “Pachynolophus maldani Lemoine, 1878”, later assigned to Propachynolophus, typifies the new genus Orolophus, under the binomen Orolophus maldani (Lemoine, 1878). The other referred species, “Propachynolophus levei Hooker, 1994” and “P. remyi Checa-Soler, 1997” are poorly documented, and both species shall be provisionally referred to as “Hyracotherium levei (Hooker, 1994) and “Hyracotherium remyi (Checa-Soler, 1997), pending new discoveries.
     
      


  PV article infos

Published in Vol 41-1 (2018)

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S.I. Data
La poche à phosphate de Ste-Néboule (Lot) et sa faune de vertebres du Ludien supérieur. 10 - Paléothérides (Perissodactyles).
Jean-Albert Remy
Published online: 25/09/1978

Keywords: Eocene; Quercy Phosphorites

https://doi.org/10.18563/pv.8.2-4.291-293

  Abstract

    La poche à phosphorite de Sainte-Néboule (Lot) a livré au cours des récentes campagnes de fouilles effectuées dans le cadre de la RCP 311 une douzaine de dents ou fragments de dents de paléothéridés à rapporter à 3 taxons. 


  PV article infos

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

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Les Dipodidae (Mammalia, Rodentia) d'Europe occidentale au Paléogène et au Néogène inférieur: origine et évolution.
Marguerite Hugueney and Monique Vianey-Liaud Logo
Published online: 01/10/1980

Keywords: Dipodidae; Late Oligocene; Quercy Phosphorites

https://doi.org/10.18563/pv.9.ext.302-342

  Abstract

    The study of three new populations of Plesiosminthuspromyarion from the "phosphorites du Quercy" and of material from "Auvergne" brings new data on european oligocene Dipodidae. They appear in Western Europe at the beginning of late Oligocene. Evolutionary trends of the group are drawn and particularly the emergence of morphotypes announcing P. schaubi, from the Coderet level, is revealed among the most recent populations of P. promyarion. Differences are attempted to be drawn between the three species : P. promyarion, P. myarion and P. schaubi by restudying the type-population of P. myarion from the aquitanian deposits of Chavroches (Allier) in comparison with two other populations from the same age and the same region. Relationships between early european, american and asiatic Dipodidae are discussed. 


  PV article infos

Published in Vol. 9, Ext (1980)

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

Keywords: Crocodilians; Dyrosoridae; Eocene; Mali; Palaeocene

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

  Abstract

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


  PV article infos

Published in Vol. 9, Ext (1980)

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Relations phylétiques de Bachitherium filhol, ruminant de l'Oligocène d'Europe Occidentale.
Denis Geraads Logo, Geneviève Bouvrain and Jean Sudre
Published online: 20/06/1987

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. 


  PV article infos

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

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Un giraffidae dans le pliocène de Montpellier ?
Claude Guérin
Published online: 31/10/1986

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. 


  PV article infos

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

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Contributions à l'étude du gisement Miocène supérieur de Montredon (Hérault). Les grands mammifères. 2 - les carnivores
Gérard de Beaumont
Published online: 15/11/1988

Keywords: anatomy; Carnivora; France; Montredon; Systematics; Upper Miocene

  Abstract

    The locality of Montredon has provided 8 species of camivores, often little documented, that are discribed and depicted. All the remains are fragmentary and generally badly preserved which lowers very much the possible precision of the taxonomic study; this one has however allowed the creation of a new subspecies. The most richlypdocumented forms are an ursid (Indarctos) and a felid (Machairodus). Issuing often from a westem Europe evolution, the carnivores are well inserted between those of the better known faunas of the "Classical Pontian" and of the lower Vallesian and this situation fits also well with their stratigraphic level, that cannot however be more accurately defined with them alone.
      


  PV article infos

Published in Vol. 18, Ext (1988)

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Mammals and stratigraphy : Geochronology of the continental mammal-bearing Tertiary of south America.
Larry G. Marshall, Robert Hoffstetter and Rosendo Pascual
Published online: 15/12/1983

Keywords: Cenozoic; Geochronology; Mammalia; South America; Stratigraphy; Tertiary

https://doi.org/10.18563/pv.13.ext

  Abstract

    The principles and practices employed in establishment and recognition of South American land mammal ages are reviewed along with previous and present concepts of distinguishing time, rock, and faunal units. Previous chronological arrangements of South American Tertiary land mammal faunas are appraised on the basis of recent geological and paleontological data. Twelve South American Tertiary land mammal ages are here recognized [from oldest to youngest, Riochican (middle to late Paleocene); Casamayoran (early Eocene); Mustersan (middle Eocene); Divisaderan (late Eocene); Deseadan (early [to middle?] Oligocene); Colhuehuapian (late Oligocene); Santacrucian (early Miocene); Friasan (middle Miocene); Chasicoan (late Miocene); Huayquerian (latest Miocene); Montehermosan (early to middle Pliocene); and Chapadmalalan (late Pliocene)]. As all except the Friasian were originally defined on the basis of Argentine faunas, these are discussed first and at length, and each is reviewed with discussion of type locality, stratigraphy, type fauna, and faunal correlations. Non-Argentine faunas are then discussed country by country in alphabetical order.

         A review is given of radioisotope dates obtained on volcanic rocks (i.e., basalts, tuffs) associated with mammalbearing beds in Argentina. Based on these age determinations and on correlation of the late Tertiary land mammals involved in the interchange between North and South America, a chronology of South American land mammal ages correlated with North American land mammal ages and European marine stages is proposed.

    It is concluded that South America was an island continent through most of the Tertiary Period (ca 65 to about 3 Ma). As a result, the land mammal fauna of South America developed in isolation and was dominated by autochthonous endemic groups. Toward the end of the Tertiary (i.e., middle Miocene) a unique faunal balance had been achieved by the descendants of the ancient inhabitants (notoungulates, litopterns, condylarths, astrapotheres, edentates, marsupials) and of later (late Eocene) waif immigrants (caviomorph rodents, platyrrhine primates). A prominent feature of this mammal fauna was the combination of carnivorous and omnivorous marsupials with native placental herbivorous ungulates, subungulates, and edentates.

    Sometime during the late Miocene, a limited but important interchange of mammalian taxa between North and South America took place. Procyonids (raccoons and their allies), a group of North American origin, first appear in South America in strata of Huayquerian Age, while members of the extinct South American ground sloth families Megalonychidae and Mylodontidae first appear in North America in early Hemphillian time. These groups dispersed along island arcs before the appearance of the Panamanian land bridge in the Pliocene (ca 3.0 Ma). Cricetine rodents, a group of North American origin, are first known in South America in strata of Montehermosan Age. The known taxa are too advanced and diversified to be considered the first of this group to invade South America. lt is believed by some workers that these rodents arrived before the Montehermosan, possibly in the late Miocene or earlier, by waif dispersal from North America.

    The isolation of South America ended with the appearance of the Panamanian land bridge, which provided a direct, dry land connection between the two Americas. Across this portal an extensive interchange of terrestrial faunas occurred, and the fossil record documents an intermingling of these long-separated land mammals faunas.

          The beginning of this interchange by land route in South America is marked by the appearance of mammals which evolved from North American emigrants in the Chapadmalal Formation of Argentina. These include a mustelid (Conepatus), a tayassuid (Argyrohyus), and four genera (Akodon, Dankomys, Graomys, Reithrodon) of cricetine rodents. The appearance of this contingent of northern animals favors the existence of the Panamanian land bridge by this time. Likewise, a large number of terrestrial vertebrates of South American origin appear in North America in beds of late Blancan Age date around 2.7 Ma. Among the mammals are Neochoerus, Erethizon, Glyptotherium, Glossotherium, Kraglievichia, and Dasypus


  PV article infos

Published in Vol. 13, Ext (1983)

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Macroscelidea, Insectivora and Chiroptera from the Miocene of east Africa.
Percy M. Butler
Published online: 15/11/1984

Keywords: Chiroptera; East Africa; Insectivora; Macroscelidea; Miocene; Systematics

  Abstract

    The East African Miocene Macroscelidea, lnsectivora and Chiroptera are revised on the basis of new material. New taxa proposed are: Miorhynchocyon, .n. gen. (Macroscelididae): Míorhynchocyon meswae, n. sp.: Pronasílío ternanensis. n. gen.. n. sp. (Macroscelididae); Hiwegicyon juvenalis, n. gen. n. sp. (Macroscelididae); Parageogale, n. gen. (Tenrecidae): Prochrysochlorinae, n. subfam. (Chrysochloridae): Propottininae, n. subfam, (Pteropodidae); Chamtwaria pickfordi, n. gen., n. sp. (Vespertilionidae). Gymnurechnínus songhorensis is synonymised with G. camptolophus. The new material provides additional information on the dentition, especially of Myohyrax oswaldi. Galerix africanus. Amphechínus rusingensis, Protenrec tricuspis and Parageogale aletris. Partial skulls are described of Amphechinus rusingensis, Protenrec tricuspis, Prochrysochloris míocaenicus and Taphozous incognita. The oldest member of the Macroscelidinae (Pronasilio) is described from Fort Ternan. Galerix africanus is closely related to G. exilis from Europe. Amphechinus rusingenesis is compared with Asiatic Oligocene Erinaceinae. The Miocene age of Crocidura is rejected. On the evidence of humeri, the following families of Chiroptera are newly reported: Pteropodidae, Nycterididae, Vespertilionidae, Molossidae. Propotto is regarded as an offshoot from the Pteropodidae, not ancestral to modern forms. Chamtwaria is a primitive vespertilionoid, provisionally placed in the Kerivoulinae. Erinaceidae probably entered Africa at the beginning of the Miocene, before 20 Ma. Faunistic differences between deposits are largely to be ascribed to differences in local environment. 


  PV article infos

Published in Vol. 14, Fasc. 3 (1984)

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Agriotherium intermedium (Stach 1957) from a Pliocene fissure filling of Xiaoxian County (Anhuei Province, China) and the phylogenetic position of the genus.
Zhanxiang Qiu and Norbert Schmidt-Kittler
Published online: 30/09/1983

Keywords: Carnivora; China; PHYLOGENY; Pliocene; skull anatomy; Ursidae

  Abstract

    A fragmentary mandible and maxilla of a small sized Agriotherium of a young individual discovered from a Pliocene fissure filling in Xiaoxian county (Anhuei Province, China) are described. Judging from the morphology of the dentition and its dimensions the new material can be identified as Agriotherium inlermedium (STACH l957). Hendey's proposition (1980) that the Agriotherium species are derived from Indarctos is reconsídered on the basis of the new documents. As a result of a more general phylogenetic discussion it can be stated, that: 1. the supposed size increase as well as other trends, leading from Indarctos to Agriotherium are untenable ; 2. there are no positive indications to assume a phylogenetic transition of these two genera. 3. there are no real arguments in favor of an adaptational reversal in the evolution of Agriotherium. Hence, many features of that genus supposed by Hendey to be derived are plesiomorphic ; 4. regardless of the previous points it is methodologícally impossible to establish direct ancestor - descendant relationships between Indarctos and Agriotherium species, as Hendey did. Based on the data available and especially on the characters of the new material from China it is more likely that Agriotherium and Indarctos are two genera which developed independently. While advanced Agriotherium species, e.g. A. africanum, resemble in some respects Indarctos by adaptational analogies, more primitive species, e.g. Agriotherium intermedium, are quite dissimilar to lndarctos. While Indarctos might be derived from an Ursavus like forerunner, Agriotherium has its roots more likely somewhere in between Ursavus and the Hemicyon-group. 


  PV article infos

Published in Vol. 13, Fasc. 3 (1983)

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Contributions à l'étude des micromammifères du gisement Miocène supérieur de Montredon (Hérault). 4 - Les chiroptères
Bernard Sigé
Published online: 30/06/1982

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

https://doi.org/10.18563/pv.12.3.133-140

  Abstract

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


  PV article infos

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

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Recherches de mammifères paléogènes dans les départements de l'Aisne et de la Marne pendant la deuxième moitié du vingtième siècle
Pierre Louis
Published online: 16/12/1996

Keywords: Biochronology; Eastern Paris Basin; Fossil localities; Mammals; paleoenvironments; Paléogène; Paleogeography

  Abstract

    A brief historical account of fossil vertebrate discoveries in the Eastern part of the Paris Basin between the beginning of the nineteenth century and 1950 is given. Other localities discovered since then are presented. A reconstruction of past landscapes is briefly elaborated. A biozonation based on mammals is proposed, from the Late Thanetian to the Middle Bartonian. Paleogeographical considerations are added. Suggestions regarding the search for new marnmal localities are made. 


  PV article infos

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

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A new vertebrate locality in the eifelian of the khush-yeilagh formation, Eastern Alborz, Iran
Alain Blieck, Farrokh Golshani, Daniel Goujet, Amir Hamdi, Philippe Janvier Logo, Elga Mark-Kurik and Michel Martin
Published online: 01/02/1980

Keywords: Devonian; Iran; khush-yeilagh formation; Vertebrate

https://doi.org/10.18563/pv.9.5.133-154

  Abstract

    A new Devonian vertebrste locality has been discovered in 1976 in the basal part of the Khush-Yeilagh Formation in the eastern Alborz Mountains of Iran. The fossils occur in a band one centimeter thick which is identifiable at other outcrops in the area. A preliminary study of the remains has yielded the following faunal list : Placodermata (Phlyctaeniida indet.. Groenlandaspididae indet.. Coccosteidae indet., Holonema sp., Ptyctodontida indet., Antiarcha indet., Bothriolepis cf. kwangtungensis), Elasmobranchii (Ctenacanthidae indet.), Acanthodii (Gyracanthus sp., « Onchus » overathensis, Ischnacanthiforme indet.), Dipnoi (? Dipteridae indet.), « Crossopterygii ›› (Onychodus cf. sigmoides, Holoptychiidae indet., Osteolepididae indet.). This fauna is older than the Middle Givetian and probably of Middle or Lower Eifelian age. Owing to its diversity, it may prove possible to use it in the future as a reference fauna for the study of the Devonian vertebrates in Central Asia and the Middle East. 


  PV article infos

Published in Vol. 09, Fasc. 5 (1980)

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Contribution à la classification des pistes de vertébrés du Trias: Les types du Stormberg d'Afrique du Sud (1).
Paul Ellenberger
Published online: 16/10/1972

Keywords: Footprints; South Africa; Stormberg; Trias

https://doi.org/10.18563/pv.5.ext

  Abstract

    Cet article explore les pistes fossiles de vertébrés du Stormberg (Trias, Afrique du Sud), révélant une diversité ichnologique inédite avec 64 ichnotypes classés en tridactyles, tétradactyles et pentadactyles. Les découvertes incluent des reptiles bipèdes comme Qemetrisauropus et Prototrisauropus, dont les empreintes suggèrent des adaptations évolutives vers la bipédie, ainsi que des pentadactyles géants comme Pentasauropus, annonçant les futurs sauropodes. L’étude combine ichnologie et restes osseux pour reconstituer des écosystèmes triasiques riches, où flore (fougères, conifères) et faune témoignent d’une transition écologique majeure avant l’essor des dinosaures. 


  PV article infos

Published in Vol. 5, Ext (1972)

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Le genre Plagiolophus (Palaeotheriidae, Perissodactyla, Mammalia): révision systématique, morphologie et histologie dentaires, anatomie crânienne, essai d'interprétation fonctionnelle
Jean-Albert Remy
Published online: 15/12/2004

Keywords: New taxa; Paléogène; perissodactyls; skull anatomy; tooth histology

  Abstract

    The genus Plagiolophus is documented, almost solely in Western Europe, from the middle Eocene up to the mid Oligocene (MP 12 to MP 25), i.e. more than for 15 MY. Seventeen species are now recorded whose two of them are new, P. ringeadei nov. sp. and P. mamertensis nov. sp. Some anatomical variations and the deflection of certain evolutionary trends justify the distinction of three subgenera, Paloplotherium, Fraasiolophus nov. and Plagiolophus s.s. The genus displays a wide range in size and weight (between 10 and 150 kg). The detailed description of the skull of several species is here given for the first time.
    Despite important evolutionary drifts during this long time span, the dentition shows a great structural homogeneity, which renders difficult the determination of fragmentary specimens or isolated teeth. It is characterized by a great heterodonty; premolars are little molarized and present a certain regression through time with paradoxically some progress in the molarization. The hypsodonty increases: the first Plagiolophus are hardly less brachyodont than Propalaeotherium, and the last ones are nearly as hypsodont as Merychippus from the early Miocene. The upper molars change from a wide crown pattern, with an open occlusal surface, lightly oblique transverse lophs and rounded internal cusps, to a narrower pattern, with a frontally constricted occlusal surface and internal lophs aligned parallel to the ectoloph. The M3/3 become always longer.

    The dental enamel displays horizontal Schreger-bands with imprecise limits occupying only the middle part of the enamel layer. The dentine is remarkable by its high rate of pericanalicular dentine. The crown cementum, lacking in earlier forms, increases to the point where it fills the occlusal valleys of the
    teeth.

    The masticatory musculature shows a increasing prominence of the temporal, with probably an important role devoted to the pterygoid muscles in lateral movements related to a two-phase type of chewing.

    The evolution of the dentition, of the masticatory musculature and of the repartition of masticatory forces indicate that the Plagiolophus have known different diets through their long evolutionary history; at first browsers they became mixed feeders and finally grazers. Their relatively long neck allowed these animals to reach different vegetal layers. The strength of the nuchal crests also suggests that they were able to have strong backwards movements of the head to pull up their food.

    This evolution of diet seems related to the slow degradation of environmental conditions attested during this period in western Europe, with the generalization of more open landscapes, increasing aridity and more marked seasons.

    Besides, a remodeling of the face is ontogenetically and along time observed, in relation with the evolution of the masticatory apparatus and especially with that of the mandibular lever arm. The postcanine diastemata become longer in the course of evolution; the free extremities of the nasals are always relatively long which contradicts the hypothesis according to which Paloplotherium may have had a trunk. At last the lineage Fraasiolophus can be distinguished by the presence of a deep malar fossa, probably related to a strong development of the maxillo-labialis superior muscle.

    The orbit is always large and tends to increase in size, which indicates a good development of the vision and its increasing role in the life relations. A peculiar type of epitympanic sinus could have been used as a resonance chamber insuring a certain amplification of sounds before their transmission to the eardrum. The endocranial cast reveals a relatively large brain with an advanced degree of gyrencephaly. Beside the role eventually played in food research and social relations, these neurophysiological abilities, also related to an advance in cursorial fitness, could have contributed to the survival of these animals facing the predation pressure of the first fissipede carnivores and the competition with new immigrant herbivores after the "Grande Coupure".
    On the basis of some shared apomorphies with the Pachynolophinae, which prevent from considering the latter as Equidae (molarization of the premolars, reduction of the premaxilla dorsal apophysis, peculiar epitympanic sinus, splitting of the jugular process), the hypothesis of an autochthonous origin of Plagiolophus issued from a form near Propalaeotherium, is once again proposed and discussed. Finally, intra-generic relationships are taken into consideration. 


  PV article infos

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

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Eggshell microstructure and porosity of the Nicobar scrubfowl (Megapodius Nicobariensis, great Nicobar island, India)
Géraldine Garcia Logo, Ashu Khosla Logo, Ashok Sahni Logo and Monique Vianey-Liaud Logo
Published online: 16/12/2008

Keywords: conductance porosity; eggshell microstructure; incubation conditions; Megapodes

https://doi.org/10.18563/pv.36.1-4.75-88

  Abstract

    The eggshell of Nicobar scrubfowl (Megapodius nicobariensis) is described for the first time. Its egg porosity is calculated and discussed with data from several taxa (another megapode, some extant and fossil reptiles including a titanosaur group) in order to compare incubation types with eggshell structure. Eggshell microstructure reflects first phylogenetic traits and does not seem to have developed major adaptative features due to the incubation conditions, except for the pore canals. 


  PV article infos

Published in Vol. 36, Fasc. 1-4 (2008)

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A femur of the Late Cretaceous giant bird Gargantuavis from Cruzy (southern France) and its systematic implications
 
Eric Buffetaut Logo and Delphine Angst Logo
Published online: 27/06/2019

Keywords: Aves; femur; France; Gargantuavis; Late Cretaceous

https://doi.org/10.18563/pv.42.1.e3

  Abstract


    A large avian femur recently discovered at the Late Cretaceous Montplo-Nord locality at Cruzy (Hérault, southern France) is referred to the giant bird Gargantuavis philoinos. The estimated mass of the bird is 57 kg, within the range of living cassowaries. The specimen provides new evidence about the anatomy of G. philoinos, notably showing that the distal end of the femur was similar to that of modern birds in having a condylus lateralis subdivided into two semicondyles. A new diagnosis of Gargantuavis philoinos is provided and the taxon is placed in a new family of basal ornithurines.
      


  PV article infos

Published in Vol 42-1 (2019)

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