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


  Article infos

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

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Contributions à l'étude du gisement Miocène supérieur de Montredon (Hérault). Les grands mammifères. 2 - les carnivores
Gérard de Beaumont
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.
      


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Published in Vol. 18, Ext (1988)

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Nouveaux Mammifères Eocènes du Sahara Occidental
Jean Sudre
Keywords: Eocene; Mammals; Occidental Sahara
 
  Abstract

    The fossil mammals collected from the Eocene of Hammada du Dra (northwest Sahara. Algeria) and two fragmentary teeth from the Lutetian of M'Bodione Dadere (Senegal) are described.
    The fossils from the northwest Sahara come from a lacustrian deposit dated by charophytes (Raskyella aff. pecki, Raskyella n. sp.. Maedleriella lavocati, Maedleriella sp. et ? Peckichara sp.) as Middle Eocene or perhaps Lower Eocene (Gevin, Feist and Mongereau, 1974). Several hyracoids (3 or 4) identified from this formation extends the age of the family Pliohyracidae Osborn in Africa. Three forms appear to belong in the genera Megalohyrax, Titanohyrax and perhaps Bunohyrax which have been know until now only from the lower Oligocene of the Fayum (M. gevini n. sp. ; T. mongereaui n. sp.. ? Bunohyrax or Megalohyrax indet.). Another hyracoidof small size is referred to a new genus, Microhyrax (M. lavocati n. sp.).
    Helioseus insolitus n. g. n. sp. is described without ordinal assignment. Azibius (Sudre, 1975) which has been the subject of questions and interpretations is reviewed.
    Only one tooth from the Lutetian of M'Bodione Dadere is complete enough to interpret. lt probably belongs to a condylarth and demonstrates for the first time, the presence of the order in Africa. The second tooth is too fragmentary for comment.
    In conclusion., the paleobiogeographic role of Africa at the end of the cretaceous and the beginning of the Cenozoic is discussed. 


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Published in Vol. 09, Fasc. 3 (1979)

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Eggshell microstructure and porosity of the Nicobar scrubfowl (Megapodius Nicobariensis, great Nicobar island, India)
Géraldine Garcia, Ashu Khosla, Ashok Sahni and Monique Vianey-Liaud
Keywords: conductance porosity; eggshell microstructure; incubation conditions; Megapodes

doi: 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. 


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

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Additions of the Geiseltal mammalian faunas, Middle Eocene: Didelphidae, Nyctitheriidae, Myrmecophagidae.
Gerhard Storch and Hartmut Haubold
Keywords: Edentata; Geiseltalian; German Democratic Republic; Lipotyphla; Marsupialia; MP 11-13
 
  Abstract

    New and hitherto unpublished mammals from the stratigraphical levels Unterkohle, Untere Mittelkohle and Obere Mittelkohle of the Geiseltal near Halle, GDR, are described (= biochronological levels MP 11-13, Geiseltalian sensu Franzen & Haubold 1986a, b). The marsupial taxa Amphiperatherium aff. maximum (MP 12), A. goethei (MP 12), and Peratherium aff. monspeliense (MP 12 and 13) are recorded for the first time. A lectotype for Amphiperatherium giselense is designated, and the alleged primate Microtarsioides voigzi is assigned to Marsupialia, incertae sedis. A new insectivore species, Saturninia ceciliensis n. sp., is described (MP 13). The anteater Eurotamandua joresi is recorded for the first time outside its type locality, Grube Messel, FRG (MP 11). The present humerus and ulna display the autapomorphic features of the myrmecophagids. 


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Published in Vol. 19, Fasc. 3 (1989)

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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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in press

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S.I. Data
Les rongeurs de Chéry-Chartreuve et Rocourt-Saint-Martin (est du bassin de Paris; Aisne, France). Leur place parmi les faunes de l'Eocène Moyen d'Europe
Bernard Comte, Maurice Sabatier and Monique Vianey-Liaud
Keywords: Biochronology; evolution; Middle Eocene; Paris basin; Rodents; systematics

doi: 10.18563/pv.37.4-5.167-271
 
  Abstract

    This paper is mainly devoted to the systematics of rodents from two middle Eocene (Bartonian) localities: Chéry-Chartreuve and Rocourt-Saint-Martin (Aisne, Eastern Paris Basin). These two localities are stratigraphically located slightly above the Auversian sands. The two faunas, which comprise 11 and 8 taxa, respectively, are very different in their composition. That of Rocourt-Saint-Martin shows strong similarities with that of the geographically very close locality of Grisolles, referred to the MP16 mammalian Reference level. The very distinct fauna of Chéry-Chartreuve includes a new species of Ailuravinae, Ailuravus nov.sp, and some teeth of the theridomyid Protadelomys, which represent archaic elements in the fauna. The most abundant species of the locality represents a new genus of primitive Theridomyidae. The presence of some teeth belonging to a new species of large Remyinae, Remys nov. sp., of Elfomys engesseri HOOKER & WEIDMANN, and a population of small dimensions referred to the genus Estellomys allow a correlation with Les Alleveys (Switzerland), with however some differences that would indicate an older age for Chéry-Chartreuve. Situated at the base of the "Marinesian" from the Bassin de Paris, this fauna is unquestionably different from those referred to the MP16 reference level and could represent an older level for which the macrofauna remains very poorly known. Conversely, the comparison of rodents from La Livinière II with those present in MP16 faunas, especially those of Robiac (Gard), shows a great similarity between both localities. This casts doubts on whether to keep this La Livinière II faunule to define the current MP15 reference level, while the biostratigraphical position of Pontils 26 (Spain), previously referred to this level, is reconsidered. Chery Chartreuse could be a good candidate for a new definition of the MP15 reference level. 


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Published in Vol. 37, Fasc. 4-5 (2012)

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Fossil snakes from the Palaeocene of Sao José de Itaborai, Brazil.Part 1 Madtsoiidae, Aniliidae.
Jean-Claude Rage
Keywords: Aniliidae s.l.; Brazil; Coniophis; Hoffstetterella; Madtsoia; Madtsoiidae; middle Palaeocene; New taxa; Snakes
 
  Abstract

    The middle Palaeocene of São José de Itaboraí (State of Rio de Janeiro, Brazil) has yielded a very rich and diverse snake fauna which includes Madtsoiidae, Aniliidae s.l., Boidae, Tropidophiidae s.l., Booidea incertae sedis, and Russellophiidae. The present article (part I) deals with Madtsoiidae and Aniliidae s.l. Madtsoiidae are represented by many vertebrae and a few skull bones. They comprise one new species assigned to the genus Madtsoia (M. camposi sp. nov.). However, the definition of the genus Madtsoia is unsatisfactory and the generic allocation might be provisional. A few elements, vertebrae only, belong to the Aniliidae s. l. Two taxa are referred to this latter group: Coniophis cf. C. precedens and Hoffstetterella brasiliensis gen. et sp. nov. The forthcoming part II will deal with Boidae.

      


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

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Ein neuer condylarthre und ein tillodontier (Mammalia) aus dem Mitteleozän des Geiseltales.
Jens L. Franzen and Hartmut Haubold
Keywords: Condylarthra; Eocene; Europe; Mammalia; Taxonomy; Tillodontia
 
  Abstract

    In the course of a revision of the Equoidea numerous dentitions as well as a partial skeleton of a Phenaeodont were discovered from the Middle Eocene lignite beds of the Geiseltal locality. These fossils are recognized as a new genus and species of Phenacodontidae : HaIlensia matthesi n.g. n.sp.. The species is present in the « untere und obere Unterkohle ›› (uUK, oUK = the lower and upper part of the Lower Coal Seam) as well as in the « obere Mittelkohle ›› (oMK = the upper part of the Middle Coal Seam). Two fragmentary upper jaws described and figured by Matthes (1977) as Propachynolophus gaudryi are also belonging to Hallensia matthesi. Thus the decisive argument for classifying the " Unterkohle " of the Geiseltal section as Lower Eocene has to be dropped. Another relict form of the Geiseltal is Esthonyx tardus n. sp. documented by a fragmentary mandible coming from the « untere Unterkohle ››. This is the latest Tillodont from Europe. Contrasting to E. munieri from the european Lower Eocene the dentition of E. tardus is morphologically more progressive. 


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Published in Vol. 16, Fasc. 1 (1986)

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The lower Miocene artiodactyls of Tagai bay, Olhon island, lake Baikal (Russia)
Inesa Vislobokova
Keywords: Artiodactyls; Mammals; Miocene; Siberia
 
  Abstract

    The mammalian fauna of the Tagai locality of Olhon Island in Lake Baikal contains six artiodactyls:
    Amphitragulus boulangeri, Lagomeryx parvulus, Stephanocemas sp., Palaeomeryx kaupi, Orygotherium aff. escheri, and Brachyodus intermedius. They are reported from Eastern Siberia for the first time. A description of teeth and limb-bones are given. An analysis of the systematic composition of the Tagai fauna allows it to be correlated with European faunas of the second part of the Early Miocene (Orleanian, MN 3-4) and permit suggestion of the existance of a united European-Siberian zoogeographical sub-area in the middle latitudes of Eurasia at that time. 


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

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Artiodactyla aus den Eozänen Braunkohlen des Geiseltales bei Halle (DDR)
Jorg Erfurt and Hartmut Haubold
Keywords: Artiodactyles; Eocene; Europe; Paleoecology; Stratigraphy; Taxonomy
 
  Abstract

    The present study of Artiodactyla from the Middle Eocene of the Geiseltal lignite beds concems systematics, biostratigraphy, and palaeoecology on the basis of 174 specimens: isolated remains to more complete skeletons. Instead of the formerly known five species of two families are now recognized 14 species of the Diacodexeidae, Dichobunidae, Cebochoeridae, and Haplobunodontidae. New species are Aumelasia maniai, Anthracobunodon neumarkensis, Masillabune franzeni. Four species of the Geiseltalfauna are definitely known from elswere, and five species are closely related to those from other European localities. Evidently the faunal situation of artiodactyls during the Middle Eocene of Europe was largely uniform. The distribution of artiodactyls within the sequence of the Geiseltal strata corroborates the biostratigraphical concept of the land mammal age Geiseltalian (Franzen & Haubold l986b) as well as the mammalian reference levels MP 11-13 (Franzen 1987). Reconstructions of the skulls and skeletons allow conclusions on the functional morphology and palaeoecology of the artiodactyls of the European Middle Eocene 


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Published in Vol. 19, Fasc. 3 (1989)

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Les rongeurs du site Pliocène à Hominidés de Hadar (Ethiope)
Maurice Sabatier
Keywords: Ethiopia; hominids; Muridae; Pliocene
 
  Abstract

    The intensive exploration of the Pliocene Hadar Formation, rich in hominid remains, led us to the discovery of several micromammals levels. ln some of them, rodents are very abundant. The stratigraphic repartition of these levels do not cover the whole fossiliferous series of the formation but takes place only in the sedimentary members from Sidi Hakoma and Denen-Dora (rancing from 3.1 - 3.2 MY to 2.8 - 2.9 MY, according to the recent geochronological data). During this gap of time, the species do not show morphological changes, what allowed us to gather, in the same taxa, forms of slighty different ages.
    Two striking facts, giving a lot of indications, characterize these small rodents'faunas. First, we notice the domination of the Muridae, as well on a qualitative way (number of species) as on a quantitative one (number of individuals). Then, it appears that, until now, two genera of these murids were known only in the south-western asiatic regions. So, we can suppose continuous biotops between Africa and Indian Subcontinent before 3 MY. In this hypothesis, the hominids had already the possibility to leave their african « cradle ››. Finally, almost all studied genera are still represented at the present time. This fact, previously observed in Laetolil, Omo, Olduvai contributes to remove hope of establishing a biochronological scale based on rodents, in tropical zone. Nethertheless, that allows to try a reconstruction of the palaeoenvironnement, by using the principle of actualism.
      


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Published in Vol. 12, Fasc. 1 (1982)

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

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


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

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Les Pseudosciuridae (Mammalia, Rodentia) de l'Eocène moyen de Bouxwiller, Egerkingen et Lissieu.
Jean-Louis Hartenberger
Keywords: Bouxwiller; cranium; Egerkingen; Middle Eocene; Rodents

doi: 10.18563/pv.3.2.27-64
 
  Abstract

    The description of new material from three classic middle Eocene localities of western Europe permits the addition of details to the systematics of primitive Pseudosciurids. The cranial anatomy of Protadelomys cartieri (STEHLIN and SCHAUB) from Egerkingen is described here and compared to that of the Adelomyines from the late Eocene, until now the only ones known. The morphologic and biometric study of the dentition of P. cartieri compared to that of P. alsaticus n. sp. from Bouxwiller and P. Iugdunensis n. sp. from Lissieu, forms respectively older and younger than P. cartieri, permits the evolutionary tendencies of the group to be demonstrated and shows that notable differences in age exist between these localities. This ensemble of forms can constitute a valuable guide lineage in the establishment of a fine stratigraphy of the period. Other less well known lineages are present at Egerkingen along with P. cartieri. They can be related to genera that have been noted int he late Eocene. In conclusion, a criticism of recent zonation proposals, made by divers authors, completes this article. 


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Published in Vol. 03, Fasc. 2 (1969)

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A reassessment of the giant birds Liornis floweri Ameghino, 1895 and Callornis giganteus Ameghino, 1895, from the Santacrucian (late Early Miocene) of Argentina.
Eric Buffetaut
Keywords: Argentina; Aves; Callornis; Liornis; Miocene

doi: 10.18563/pv.40.2.e3
 
  Abstract

    The status of the giant bird taxa Liornis floweri and Callornis giganteus from the Santa Cruz Formation (late Early Miocene) of Patagonia, first described by Ameghino (1895) is reassessed on the basis of a re-examination of the type material at the Natural History Museum, London. Liornis floweri, which lacks a Pons supratendineus on the tibiotarsus and has an unbifurcated Canalis interosseus distalis on the tarsometatarsus, is clearly a brontornithid and is considered as a junior synonym of Brontornis burmeisteri. Ameghino’s replacement of Callornis by Eucallornis is unjustified. Callornis giganteus is a chimera based on a phorusrhacid tarsometatarsus (probably belonging to Phorusrhacos longissimus) and a brontornithid tibiotarsus. The latter can be considered as the lectotype of Callornis giganteus, which may represent a small morph of Brontornis burmeisteri or a distinct taxon. It is referred to here as Brontornithidae indet. The tarsometatarsus described by Dolgopol de Saez (1927a,b) as Liornis minor and considered by her as a gracile brontornithid apparently has a bifurcated Canalis interosseus distalis and should therefore be placed among the Phorusrhacidae. 


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Published in Vol.40-2 (2016)

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A new study of the anthracotheres (Mammalia, Artiodactyla) from pondaung formation, Myanmar: systematics implications
Aung N. Soe
Keywords: Anthracohyus; Anthracokeryx; Anthracotherium; Pondaung Formation; sexual dimorphism; Siamotherium; South East Asia; Taxonomy

doi: 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. 


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

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Nouvelle quantification de l'Hypsodontie chez les Theridomyidae : l'exemple de Theridomys ludensis nov. sp.
Monique Vianey-Liaud
Keywords: dental morphology; evolution; Hypsodonty; Oligocene; Theridomyidae
 
  Abstract

    A new example of parallelism in the dental pattern ofthe Theridomyidae is illustrated by the description ofa new species: Theridomys Iudensis from the standard level of Antoingt (middle Oligocene). Considering the occurence ofthis parallelism phenomenon. the use of numerous qualitative and quantitative criteria is essential to characterize the different stages ofthe different evolutive lineages. Thus, a new simple parameter is proposed (CHY = H+l/0,5 L) to estimate hypsodonty of the medium hypsodont Rodentia. 


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Published in Vol. 15, Fasc. 3 (1985)

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Les vertébrés fossiles de Colombie et les problèmes posés par l'isolement du Continent sud-Américain.
Jaime de Porta
Keywords: Columbia; Cretaceous; Fauna; Quaternary; South America

doi: 10.18563/pv.2.2.77-94
 
  Abstract

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


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

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Etude du crâne de Pachynolophus lavocati n. sp. (Perissodactyla, Palaeotheriidae) des Phosphorites du Quercy
Jean-Albert Remy
Keywords: Perissodactyla; Quercy phosphorites

doi: 10.18563/pv.5.2.45-78
 
  Abstract

    The genus Pachynolophus, one of the poorest known of the Palaeotheriidae, includes the brachyodont forms with reduced and non-molariform premolars and with upper molars lacking a mesostyle. Quantitative characters (divers surface indications and elongation of the teeth), while demonstrating a close relationship to Hyracotherium, permit a better differentiation of the genus, confirm its specific splitting, and permit the distinction of three lineages. The skull from Memerlein is taken as the type of a new species, P. Iavocati, of which the dentition is extremely characterized by its lophiodonty, the strong reduction of the premolars and the reduction of the cingula. This characterization testifies to a late age which extends the existence of the genus quite near to the Eocene-Oligocene limit. Compared with the only two skulls known of related species (Hyracotheríum vulpiceps and Pachynolophus Iivinierensis), that from Memerlein is distinguished by progressive characters affecting diferent regions but most particularly the braincase; it is not possible, however, to isolate within this evolution the part which leads to a systematic differentiation. Modernization is translated by a considerable increase in size of the braincase, principally in the frontal region, a development of the facial region with anterior displacement of the dental series and a greater specialization of the masticatory apparatus. This evolution parallels the history of the Equidae of the North American early Tertiary, but certain particularities, the form of the alisphenoid, the presence of an anterior frontal foramen, and the structure of the paroccipital apophysis, testifies to the independance of the European forms. 


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Published in Vol. 05, Fasc. 2 (1972)

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Etude de la Variabilité chez Lophiodon lautricense Noulet
Jean Sudre
Keywords: Cheek teeth; Eocene; Lophiodon; Variability

doi: 10.18563/pv.4.3.67-95
 
  Abstract

    The biometric and morphologie variability of the cheek teeth in the end-of-the-phylum species Lophiodon lautricense Noulet studied in this note, reposes on the observation of about 800 teeth. These were revealed to be little variable in absolute dimensions. The considerable morphologie variability in the upper premolars permitted the problem of the molarization process to be taken up. An hypothesis concerning the order of eruption of the cheek teeth is formulated based on an examination of a large number of milk dentitions. In conclusion, it is suggested that reservations be held on the value of dental characters classically used in systematics for the group under consideration. 


  Article infos

Published in Vol. 04, Fasc. 3 (1971)

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