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Page 10 of 19, showing 20 record(s) out of 365 total

Un crane de Chalicothere (Mammalia, Perissodactyla) du Miocène supérieur de Macédoine (Grèce) : remarque sur la phylogénie des Chalicotheiinae
Louis de Bonis Logo, Geneviève Bouvrain, George D. Koufos and Pascal Tassy Logo
Published online: 14/06/1995

Keywords: Chalicotheriidae; Cladistics; Greece; Miocene; Perissodactyla; PHYLOGENY

  Abstract

    The discovery in the Turolian (Late Miocene) of Dytiko 3 (Macedonia, Greece) of a complete skull with mandibles and cervical vertebrae, atlas and epistropheus, is a very important contribution to the knowledge of the subfarnily Chalicotheríinae. After the description, the comparison with other specimens of Miocene chalicotheres permits the revival of the generic name Macrotherium with a new species M. macedonicum. This genus is mainly characterized by a short snout and an inflated cerebral skull. It coexists during the Miocene with Chalicotherium. A cladistic analysis leads to conclusion that the species which has been described from the Early Middle Miocene of Rusinga must be identified as the type-species of a new genus: Butleria.





      


  PV article infos

Published in Vol. 24, Fasc. 1-2 (1995)

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Mode de vie et affinités de Paschatherium (Condylarthra, Hyopsopontidae) d'après ses os du tarse
Marc Godinot Logo, Thierry Smith Logo and Richard Smith
Published online: 16/12/1996

Keywords: Astragalus; Calcaneum; Condylarthra; Eocene; Functional morphology; Paschatherium; PHYLOGENY

  Abstract

    Tarsals that can be confidently attributed to Paschatheríum dolloi from Dormaal (Belgium) are described. The astragalus is short; its broad neck is set at an angle of 30 degrees to the trochlea. The trochlea is pulley-shaped and proximally extended. There is no astragalar foramen. The medial tibial facet extends distally in a cup deeply excavated in the neck and buttressed. The sustentacular facet extends toward the navicular facet but is not fully confluent with it. The calcaneum bears a proximo-distally extended proximal facet for the astragalus. A relatively large peroneal tubercle projects from the body, and is situated distally. Functionally, the trochlea indicates extensive flexion-extension movements of the foot. Calcaneo-astragalar facets indicate sliding and rotation between the two tarsals. The inclination of the navicular facet suggests frequent foot inversion. The peroneal tubercle reflects good muscular capacities for foot rotation. Overall morphology is interpreted as a scansorial adaptation similar to that of sciurids.Comparisons are made with the tarsals of Macrocranion vandebroeki from Dormaal and Hyopsodus paulus from the Bridgerian of Wyoming. Some similarities between the astragali of Paschatherium and Macrocraníon (trochlea) are interpreted as convergences for rapid locomotion. However absence of mobility at the lower ankle and midtarsal joints in M. vandebroekzi suggests that this species was cursorial, as is known for M. tenerum from Messel. Similarities in the calcanea of Paschatherium and Hyopsodus are probably the result of close phylogenetic relations, and confirm the placement of Paschatherium in the hyopsodontids. The differences in the calcanea of Paschatherium and Macrocranion underline that Paschatherium is distinct from erinaceomorph insectivores. The differences in astragalar morphology between Paschatherium and Hyopsodus show that a marked adaptive divergence separates the two genera. We speculate about the common occurrence of a deep tibial cup (“cotylar fossa”) and a pulley-shaped trochlea in Paschatherium and hyracoids, suggesting that an adaptive scenario similar to that having led to Paschatherium (scansoriality) might explain the acquisition of the peculiar hyracoid tarsal characters; such a scenario contradicts the concept of Pantomesaxonia. Other peculiar characters of Hyopsodus suggest that hyopsodontids might be given more consideration in the search for hyracoid (and tethythere) origins. 


  PV article infos

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

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The Late Cretaceous nesting site of Auca Mahuevo (Patagonia, Argentina): eggs, nests, and embryos of titanosaurian sauropods.
Luis M. Chiappe Logo, Rodolpho. . Coria, Frankie D. Jackson and Lowell Dingus
Published online: 15/12/2003

Keywords: Argentina; Eggs; embryos; Late Cretaceous; nests; Patagonia; titanosaurian sauropods

  Abstract

    The late Cretaceous Auca Mahuevo nesting site (Neuquén Province, Argentina) has produced a large number of sauropod eggs, many of them containing the remains of embryos. Research at this site has generated important information about the development of the embryos, the morphology and eggshell microstructure of the eggs, and the reproductive behavior of sauropod dinosaurs. Cranial features present in the embryos have allowed their identification as those of titanosaurian sauropods. Differences in the texture of the sediments that contain some of the egg-clutches have illuminated their nest architecture. Microstructural studies of eggshells have expanded our knowledge of their variability and the incidence of pathologies within a reproductive titanosaurian population. Maps showing the spatial distribution of eggs and clutches. the stratigraphic distribution of the egg-beds, and the sedimentological context in which they are contained, have provided the basis for several inferences about the nesting behavior of these dinosaurs. 


  PV article infos

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

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D'important restes de Diplobune minor FILHOL à Itardies (Quercy)
Jean Sudre
Published online: 15/11/1974

Keywords: Diplobune; Quercy Phosphorites

https://doi.org/10.18563/pv.6.1-2.47-54

  Abstract

    Voici un résumé concis en trois phrases :
    Cet article décrit des restes importants de Diplobune minor Filhol, une espèce d’Anoplothériidé, issus du gisement d’Itardies (Quercy), découvert lors de la campagne de fouille de 1972. Le matériel comprend deux crânes, plusieurs mandibules et des éléments du squelette, notamment des pattes postérieures complètes, permettant une étude anatomique détaillée. L’espèce, auparavant mal connue, est caractérisée par une denture distinctive, avec des incisives puissantes, des prémolaires carénées, et des molaires à structure archaïque, ainsi que par des particularités squelettiques comme des métapodes allongés et des phalanges planes.
    L’étude de ces restes permet de préciser la morphologie et la systématique de cette espèce, tout en soulignant la nécessité d’une analyse plus approfondie des éléments anatomiques. La faune d’Itardies, corrélée avec celle de Montalban, suggère que Diplobune minor est soit plus récente que le Sannoisien supérieur classique, soit moins localisée chronologiquement qu’on ne le pensait. 


  PV article infos

Published in Vol. 06, Fasc. 1-2 (1974)

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Nouveaux gisements à rongeurs dans les molasses oligo-miocènes de la région toulousaine
Francis Duranthon Logo
Published online: 11/02/1993

Keywords: Cricetidae; Eomyidae; GIiridae; Miocene; Oligocene; Rodents; Sciuridae; Southern France

  Abstract

    The fauna from three new rodent localities (Castelmaurou, Grépiac-carrière et Grépiac-rive gauche) from Oligo-Miocene molasses of the Toulouse area is described. The one from Colomiers is completed. 11 species belonging to 4 families (Cricetidae, Eomyidae, Gliridae, Sciuridae) are present. The Miocene localities of Grépiac-carrière and Colomiers are correlated with Balizac, La Brète, Lambert and Lespignan. Grépiac-rive gauche is just a little older than these sites. Castelmaurou is somewhat younger than La Milloque and belongs to Oligocene. 


  PV article infos

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

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Mammals and stratigraphy of the continental mammal-bearing Quarternary of South America
Larry G. Marshall, Annalisa Berta Logo, Robert Hoffstetter, Rosendo Pascual, Osvaldo A. Reig, Miguel Bombin and Alvaro Mones Logo
Published online: 16/12/1984

Keywords: Geochronology; Mammalia; Quaternary; South America; Stratigraphy

  Abstract

    Previous chronological arrangements of South American Quaternary land mammal faunas are appraised on the basis of current geological and paleontological data. Three South American late Pliocene-Pleistocene land mammal ages are conventionally recognized, from oldest to youngest, the Uquian, Ensenadan, and Lujanian ; all are defined on Argentine faunas.

         The Uquian is based fundamentally and historically on the fauna from the Uquía Formation in Jujuy Province, northwestern Argentina. Important known formations in Argentina yielding Uquian Age faunas include the sub-surface Puelche Formation (or Puelchense) near the city of Buenos Aires, and the Barranca de Los Lobos and Vorohué Formations between Mar del Plata and Miramar, Buenos Aires Province. A tentative subdivision is propos-ed for the Uquian into three subages based on knowledge of the Mar del Plata-Miramar sequence, from oldest to youngest, the Barrancalobian, Vorohuean, and Sanandresian. In Argentina the Uquian is presently marked by the first known record of Scelidodon, Hydrochoeropsis, Ctenomys, Canidae, Ursidae, Gomphotheriidae, Equidae, Tapiridae, Camelidae, Cervidae, and the last known record of Thylatheridium, Thylophorops, Dankomys, Eumysops, Pithanotomys, Eucoelophorus, Hegetotheriidae, Sparassocynidae, and Microtragulidae.

    The Ensenadan Age is based on the fauna from the Ensenada Formation near the city of Ensenada, Buenos Aires Province. In Argentina the Ensenadan is marked by the first known record of Lomaphorus, Neothoracophorus, Plaxhaplous, Cavia, Lyncodon, Lutra, Galera, Smilodon, Dicotyles, Lama, Vicugna, the last known record of Orthomyctera, and the only known record of Brachynasua.

         Typícal beds of late Lujanian Age in Argentina consist of fluvial deposits occupying stream channels, and shallow basins, often incised into beds of early Lujanian (i.e. Bonaerian of early workers) and Ensenadan Age. The Lujanian Age is based on a fauna from beds along the Rio Luján, about 65 km west of the city of Buenos Aires, Buenos Aires Province. The Lujanian in Argentina is marked by the first record of Equus, Chlamyphorus, and Holochilus, and the last record of Megatherioidea, Glyptodontoidea, Arctodus (=Arctotherium), Smilodon, Litopterna, Notoungulata, Proboscidea, Equidae, Morenelaphus, and Palaeolama.

       These land mammal ages are often difficult to recognize in other South American countries. The compositions of South American Pleistocene faunas vary with the environment. Some taxa were widely distributed in fossil deposits throughout the continent, but their occurrences need not reflect synchroneity. This is a result of changing climates and habitats in time. Consequently, proposed intracontinental correlations need confirmation based on magnetostratigraphy and a radioisotope time scale. Paleontologic characterizations of these land mammal ages (i.e. first and last record, and guide fossils) are useful for much of Argentina, but extensions to most of the other parts of South America are at best tenuous.

    The majority of known non-Argentine Pleistocene faunas are believed to be Lujanian in age. Possible non Argentine early Pleistocene (Uquian) faunas include Ayo Ayo and Anzaldo in Bolivia, and Cocha Verde in southern Columbia. A possible middle Pleistocene (Ensenadan or early Lujanian) fauna is the Chichense of Ecuador. Paleomagnetic and radioisotopic date (MacFadden et al., 1983) clearly indicate that the greater part of the Tarija fauna (Bolivia) is Ensenadan in age.

      The end of the Pleistocene and beginning of the Holocene in South America is marked by extinction of nearly all large mammalian herbivores and their specialized large predators. Radiocarbon age determinations suggest that large scale extinctions of megafauna occurred between 15,000 and 8,000 yrs. B.P. (years before present). 


  PV article infos

Published in Vol. 14, Ext (1984)

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Mammals and stratigraphy : the Paleocene of Europe
Donald E. Russell, Jean-Louis Hartenberger, Charles Pomerol, Sevket Sen Logo, Norbert Schmidt-Kittler and Monique Vianey-Liaud Logo
Published online: 01/12/1982

Keywords: Europe; Mammalia; Mammalian biochronology; Paléogène; Stratigraphy

https://doi.org/10.18563/pv.12.ext

  Abstract

    The mammalian faunas of the Paleogene of Europe and their localities are reviewed with comments on problems of European stratigraphy (epoch, stage and substage limits) and on the possibilities of faunal migrations. Radiometric dating is discussed. A stratigraphic scale for the Paleogene is presented, as well as a refined system of sequential faunal levels. 


  PV article infos

Published in Vol. 12, Ext (1982)

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La palichnofaune de vertébrés tétrapodes du permien supérieur du Bassin de Lodève (Languedoc-France).
Georges Gand, Jacques Garric, Georges Demathieu and Paul Ellenberger
Published online: 15/09/2000

Keywords: Footprints; France; Languedoc; Lodève basin; new ichnotypus; Saxonian; Upper Permian

  Abstract

    Near "la Lieude", in the Lodève basin, more than a thousand of footprints are distributed in a twenty of trackways which amounts to 220 m length. They have been found on calcareous siltstone level in the B site named also "Réserve Naturelle Volontaire". This last is located in the Saxonian summit dated Upper Permian. "La Lieude" tracks are described by using statistical methods then they are compared with others from the world Permian. What allows to distinguish 4 following ichnotaxa: Lunaepes ollierorum nov.ichnosp., Merifontichnus thalerius nov. ichnogen. and nov. ichnosp., Planipes brachydactylus nov.ichnosp. and Brontopus circagiganteus nov. ichnosp. All these traces are attributed with possibility or probability to Therapsida or to Therosauria, except Brontopus circagiganteus nov. ichnosp. that could be due to Caseamorpha. All these animals whose sizes have been estimated between l and 5 m lived probably in a playa environment.The biological and sedimentological data from "la Lieude" footprints levels compared with informations provided by the tracks orientations, suggest the following scenario. Animals coming from the North have crossed a sandy channel bank with plants zones by directing to the South for the majority. Maybe, they were going to the lacustrine part of the playa, close to "la Lieude" footprints that they have just trampled on. 


  PV article infos

Published in Vol. 29, Fasc. 1 (2000)

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Etude paléoneurologique comparative de Parabos Cordieri (De Christol), un bovidae (Mammalia, Artiodactyla) du Pliocène d'Europe Occidentale.
Catherine Gromolard
Published online: 31/03/1982

Keywords: Bovidae; endocranial cast; Europe; Pliocene

https://doi.org/10.18563/pv.12.2.57-74

  Abstract

    A skull of Parabos cordieri, undamaged by fossilisation, allows us to make an endocranial cast, which is compared to those of Bos taurus, Boselaphus tragocamelus and Hippotragus equinus. These are studied by general form (shape, volume, « rolling-up›› and inclination), and by detailed morphology (gyri and sulci patterns, rete mirabile, importance of rhinencephalon and cerebellum).
    A preliminary study is made in order to recognize convolution topography, gyri, sulci, and the various encephalic regions as clearly on an endocranial cast as on a bare encephalon; an intermediate stage is the study of an encephalon covered with «soft» meninges.
    The comparative study reveals great similarity between the endocranial cast of Parabos cordieri and that of Boselaphus tragocamelus, both belonging to the tribe Boselaphini. On the other hand, a marked differences separates the cast of Parabos cordieri from that of Bos taurus, representing the tribe Bovini to which Parabos cordieri had been referred. The endocranial cast of Hippotragus equinus, which had long been considered the descendant of Parabos cordieri, is also quite different from that of Parabos


  PV article infos

Published in Vol. 12, Fasc. 2 (1982)

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Two new scyliorhinid shark species (Elasmobranchii, Carcharhiniformes, Scyliorhinidae), from the Sülstorf Beds (Chattian, Late Oligocene) of the southeastern North Sea Basin, northern Germany.
Thomas Reinecke
Published online: 30/04/2014

Keywords: Chattian; Elasmobranchii; North Sea Basin; Scyliorhinidae; Scyliorhinus

https://doi.org/10.18563/pv.38.1.e1

  Abstract

    Based on isolated teeth two new scyliorhinid shark species, Scyliorhinus biformis nov. sp. and Scyliorhinus suelstorfensis nov. sp., are described from the Sülstorf Beds, early-middle Chattian, of Mecklenburg, northeastern Germany. They form part of a speciose assemblage of necto-benthic sharks and batoids which populated the warm-temperate to subtropical upper shelf sea of the south-eastern North Sea Basin. 


  PV article infos

Published in Vol.38-1 (2014)

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La poche à phosphate de Ste-Néboule (Lot) et sa faune de vertebres du Ludien supérieur. 11- Créodontes
Brigitte Lange-Badré
Published online: 25/09/1978

Keywords: Creodonta; Eocene; Quercy Phosphorites

https://doi.org/10.18563/pv.8.2-4.295-299

  Abstract

    The teeth and the astragale of the Creodonta from Ste-Néboule (Lot) are referred to Hyaenodon brachyrhynchus. Isolated teeth fit morphologically the material from La Débruge (Middle Ludian). However, biometric analysis suggests an Upper Ludian age. 


  PV article infos

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

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Observations sur l'anatomie crânienne du genre Palaeotherium (Perissodactyla, Mammalia): mise en évidence d'un nouveau sous-genre, Franzenitherium
Jean-Albert Remy
Published online: 01/12/1992

Keywords: Palaeotherium; Paléogène; Perissodactyla; skull anatomy; Systematics

  Abstract

    The skull remains referred to the genus Palaeotherium are recorded and described. Biometrical tests are made to elucidate intrageneric allometric relationships and to allow comparisons with various other perissodactyls. Apart from the well known shortness of post canine diastems and deepness of the narial opening, the genus is characterized by a great lengthening of the splanchnocranium, owing to a spreading of the post-orbital facial region, by a reduced area of the eye-socket and by the prevalence of the temporal muscle with regard to the masseter; this original shape of the masticatory apparatus needs to be related to the morphology of the jugal teeth and particularly to their  asymmetrical semi-hypsodonty.
        These animals, whose running ability was evidently poor, appear to have been adapted to rather closed environments, feeding on relatively soft vegetable matter; olfactory sense was likely to play a leading part in interindividual and environmental relationships. Such evolutionary trends might explain the disappearance of most of them, as clirnatic conditions deteriorated at the end of the Eocene, before the "Grande Coupure" which affected mammalian faunas at that time.
          Although the present paper is not directly concemed with phylogenetics, it invalidates the supposed ancestor-descendant relationship between P. castrense and P. magnum, and it suggests a possible emergence of the P. medium lineage from a P. siderolithicum stock. Moreover, the structure of the post-orbital facial area allows the  erection of a new sub-genus, Franzenitherium, for the  species lautricense and duvali.

      


  PV article infos

Published in Vol. 21, Fasc. 3-4 (1992)

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Premières données sur les rongeurs de la formation de Ch'orora (Ethiopie) d'âge Miocène supérieur. I: Thryonomyidés
Jean-Jacques Jaeger Logo, Jacques Michaux and Maurice Sabatier
Published online: 01/10/1980

Keywords: Ethiopia; Paraulacodus; Rodents; Upper Miocene

https://doi.org/10.18563/pv.9.ext.365-374

  Abstract

    The genus Paraulacodus has been collected in the Ch'orora formation of Upper Miocene age, in Ethiopia. The new species, P. johanesi n. sp.. is more evolved than the previously described indian species P. indicus HINTON of the Siwalik Hills area. The morphological gap between P. johanesi and the present Thryonomys is still important. 


  PV article infos

Published in Vol. 9, Ext (1980)

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Les nouvelles faunes de rongeurs proches de la limite mio-pliocène en Roussillon. Implications biostratigraphiques et biogéographiques
Jean-Pierre Aguilar, Jacques Michaux, Bernadette Bachelet, Marc Calvet Logo and Jean-Pierre Faillat Logo
Published online: 29/04/1991

Keywords: Arvicolidae; Cricetidae; Gliridae; Miocene; Muridae; Pliocene; Rodents; Southern France

  Abstract

    Three new fossiliferous localities, two of karstic origin, Castelnou 3 and Font Estramar, respectively Late Upper Miocene and Lower Pliocene, and one of lacustrine origin, Thuir, Lower Pliocene, add data about the transition between Miocene and Pliocene faunas of rodents in southern France. An unexpected association of taxa was present in the late Upper Miocene, including between others, Myocricetodon, Hispanomys, Ruscinomys, Cricetus barrierei, Promimomys and a new species of Stephanomys, S. dubari nov. sp. Myocricetodon is still known in the Lower Pliocene. It is shown that the large field-mice known since the Late Upper Miocene belong to two different lineages, on one side, A. jeanteti, on the other side, A. gudrunae followed by A. gorafensis. Biochronological and biogeographical implications are discussed. 


  PV article infos

Published in Vol. 20, Fasc. 4 (1991)

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Contributions à l'étude du gisement Miocène supérieur de Montredon (Hérault). Les grands mammifères. 8 - Analyse paléoécologique de la faune mammalienne
Serge Legendre Logo
Published online: 15/11/1988

Keywords: France; Mammalia; Montredon; Paleoecology; Upper Miocene

  Abstract

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


  PV article infos

Published in Vol. 18, Ext (1988)

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Leptacodon nascimentoi n,sp., un nouveau Nyctitheriidae (Mammalia,Lipotyphla) de l'Eocène inférieur de Silveirinha (Baixo Mondego, Portugal)
Carmen Estravis
Published online: 16/12/1996

Keywords: Eocene; Leptacodon; Lipotyphla; Mammals; Nyctitheriidae; Portugal; Silveirinha

  Abstract

    In this article is described a new species of Nyctitheriidae with primitive characters: Leptacodon nascimentoi n. sp. from the early Eocene of Silveirinha (Portugal). 


  PV article infos

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

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

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

  Abstract

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


  PV article infos

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

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

Keywords: archosaurian eggshells; avian egg; Experimental taphonomy; geochemical analysis; pyritisation; Upper Cretaceous

  Abstract

    We experimentally explore the early taphonomic stages involving the decay and biodegradation of buried eggs and eggshells. Unfertilised commercial chicken eggs and eggshell fragments were buried in plastic containers and were kept under controlled conditions for eight months. Half of the containers were filled with marl, and the remainder with sand. All were saturated with fresh tap water, acidified water, sulphate water, or seawater. They were kept in the dark at 23.4-26 °C, except one, which was kept in a heating chamber at 37.4°C. We expected that different burial conditions would produce distinct taphonomic outcomes. Instead, the taphonomic alterations of buried eggs parallel that of the alteration of egg proteins (i.e., denaturation and/or putrefaction) with an additional role played by the eggshell. Mummification, encrustation, distortion and fragmentation, and necrokynesis (vertical displacement) depend on organic matter decay. The experiment identifies environmental conditions that may favour or actively promote these taphonomic processes. Of these, early pyritization is one of the most relevant. For comparative purposes, samples of fossil and extinct eggshell representing three distinct environmental burial conditions were examined. These included Megaloolithus, Caiman crocodilus, and Struthio camelus ootypes. The geochemical analysis of these eggshells showed no significant differences among the chemical variables of these fossil and extant ootypes. Eggshells exhibited a stable composition over a range of experimental conditions. 
      


  PV article infos

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

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Analyse d'ouvrage: “J.J. THOMASON (Ed.): Functional morphology invertebrate paleontology (1995)”
Jacques Michaux
Published online: 18/03/1996

Keywords: Book review; Functional morphology

  Abstract

    Functional morphology invertebrate paleontology, édité par Jeffrey J. THOMASON, 1995. Cambridge University Press, xi + 277 p. ISBN 0-521-44095-5, f. 45,00 ($ 69,95).

    La morphologie fonctionnelle appliquée aux fossiles demeure un sujet à la fois passionnant et important. Passionnant, car elle s'adresse à des êtres disparus, aux combinaisons de caractères parfois inattendues et sans contrepartie chez les formes actuelles. Sujet important, car il faut, au delà de la constatation classique de l'adéquation de la forme des organes à leur fonction, expliquer l'origine des structures par évolution. L'évolution ou descendance avec modification, implique que les êtres vivants sont reliés les uns aux autres et qu'i! est possible de tenter à l'aide d'un raisonnement par inférence, la caractérisation des ancêtres en fonction des traits des formes auxquelles ils ont donné naissance. Mais il faut ajouter que par sa fonction, la structure relie immédiatement l'animal à son milieu puisqu'elle assure un rôle biologique. 


  PV article infos

Published in Vol. 25, Fasc. 1 (1996)

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Nouveaux Mammifères Eocènes du Sahara Occidental
Jean Sudre
Published online: 01/11/1979

Keywords: Eocene; Mammals; Occidental Sahara

https://doi.org/10.18563/pv.9.3.83-115

  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. 


  PV article infos

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

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