La faune de Rongeurs d'Escamps (Lot) bien que relativement pauvre en espèces (dix) s'avère riche d'enseignement pour les Rongeurs de l'Oligocène inférieur d'Europe Occidentale. Cette periode semble caracterisée par une cladogenèse des Théridomyines. A Escamps, un nouveau genre (Patriotheridomys) est décrit ainsi qu'une nouvelle espèce de Theridomys. Avec Oltmamys platyceps, décrit ici plus complètement et désormais bien situé stratigraphiquement, les deux espèces précédentes constituent un ensemble original du Sud de la France. A la même époque, en Angleterre, Allemagne et Espagne, des espèces «régionales» de Théridomyinés se dersifient.  A côté de ces formes qui ne semblent pas franchir la «Grande Coupure» sont représentées deux lignées d'Issiodoromyinés (Elfomys sp et Pseudoltmomys cuvieri), une de Théridomyiné (T. (Blainvillimys) rotundidens) ainsi qu'un Gliridé, Gliravus priscus (que l'on différencie nettement de la deuxième lignée des Gliravus oligocènes : G.  meridionalis -> G. majori). On retrouve ces formes dans les gisements plus récents du niveau de Hoogbutsel où elles sont à peine plus évoluées. Le fait que les degrés évolutifs de ces lignées soient très proches laisse supposer que le laps de temps séparant les niveaux d'Ecamps et Hoogbutsel fut relativement court. 

Pour la première fois un spécimen de lagomorphe a été récolté en Quercy. L'intérêt de ce fossile tient surtout à son âge géologique inattendu, qui recule considérablement la date de première apparition en Europe de cet ordre de mammifère, Ceci nous paraît justifier une nouvelle réflexion sur la « grande coupure» oligocène, 

Abstract not available 

A short review of the genera and species of snakes from the Quercy's phosphorites described by former authors is followed by the study of specimens recently collected. Most of these latter specimens belong to the Aniliidae, Boidae, Colubridae and to the Scolecophidia; the precise systematic position of some of them is not defined yet. The following genera and species are described: Eonilius europae nov. gen. and nov. sp., Platyspondylia lepta nov. gen. and nov. sp., Coluber cadurci nov. sp. and Dunnophis cadurcensis nov.  sp.; a species described by de Rochebrune (Palaeopython filholi) is revised. One of the most important conclusions of this study is that the Colubridae appear as early as the Upper Eocene. The stratigraphic repartition of these snakes shows that the rich Upper Eocene fauna is followed by the very reduced fauna of the Lower Oligocene; then the oligocene «Grande Coupure» corresponds to a very important faunistic renewal. The fauna remains poor and little diversified during the beginning of the Middle Oligocene after which there is a new faunistic explosion. 

Of the ten cricetid species from the Oligocene of Western Europe, attributed until now to the genus Eucricetodon, only four prove to be utilizable - E. atavus, E. huberi, E. praecursor, E. collatum - to which it is possible to add two forms newly described: E. huerzeleri and E. quercyi. The evolullon of the genus Pseudocricetodon is also the subject of new observations. The study of the dental morphology allows us to distinguish in these two genera three lineages beginning in the middle Oligocene:

- Lineage P. montalbenensis-P. thaleri (from Montalban to Goderet), of small size, without
increase in size.
- LineageE. atavus-E. infralactorensis (from Hoogbulsel to Estrepouy), of middle size, with a regular increase in size.
- Lineage E. huerzeleri-E. haslachense (level of Montalban to that of Estrepouy), of large size, with an increase in size.

Two other forms are equally represented in these loealitles: Heterocricetodon aff. helbengi and Melissiodon quercyi. It has been possible to attribute a precise age (zone of "Cournon") to the last species, which has been defined by Schaub (l925) from material in the Old Quercy collections. The genera Pseudocricetodon, Eucricetodon, ? "Cricetodon", Leydimys, Eumys, differentiated at the beginning of the middle Oligocene in Europe, Asia and North America, seem to derive from a common ancestral group. The place of origin of this group could be situated in Asia. 

Abstract not available 

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. 
  

An increasing fossil record of dinosaur eggs and eggshells allows putting ootaxa within a chronostratigraphic framework, in order to study their distribution pattern leading eventually to their use as biochronological markers. For these purposes, high-quality data exists in four major regions; North America, South America, Europe and Asia (Central Asia and India). Most of the highly diverse dinosaur egg record has been dated as Latest Cretaceous in age (Campanian-Maastrichtian), reaching the Cretaceous-Tertiary boundary closer than the dinosaur bone record. However, dating continental sections is problematic and need to be carefully verified, as it appears when comparing the European dinosaur eggshell record from two well-studied areas. Ootaxa distribution in both sides of the Pyrenees (Tremp and Aix basins) shows comparable oospecies successions, but different chronology. This disagreement probably indicates that one or both successions have a wrong chronostratigraphic calibration.  

Le premier Symposium International sur les ceufs de dinosaures et leurs petits a connu un francs succès, à Isona, en Catalogne (Espagne) en 1999. I1 faisait suite à la publication en 1994 d'un premier ouvrage "Dinosaurs eggs and babies" édité par K. Carpenter, K. Hirsch et J. Homer. Entre 1994 et 1999, les nouvelles découvertes ont augmenté significativement, notamment celles d'ceufs embryonnés, et le nombre de chercheurs impliqués dans ce domaine a accompagné cet accroissement. Jusque là, l'étude de ces objets, les coquilles d'ceufs, est restée longtemps marginale, faute d'une méthodologie scientifique appropriée. 

New populations of the genus Megacricetodon have recently been discovered in Southern France.Two new species are defined: M. lemartineli n. sp. and M. fournasi n. sp., their stages of evolution are intermediate between those of M. gersii and M. roussillonensis. Morphological and biometrical analysis indicate the presence of only one lineage: M. collongensis--M. collongensis-gersii--M. gersii--M.lemartineli nov. sp.--M. fournasi nov. sp. and M. roussillonensis. This observation allows to refine the chronology based on rodents, for the Late Early Miocene and the Middle Miocene in the Southern France.
Comparisons with some iberian species are done. The validity of the French species M. bezianensis and M. bourgeoisi is discussed. 

A new Tertiary megadermatid is described from Rackham's Roost Site, a Pliocene limestone cave deposit on Riversleigh Station, northwestern Queensland, Australia. It appears to represent the first Australian record of Megaderma GEOFFROY, 1810, a genus otherwise known from Tertiary African and European taxa and the living Asian species M. spasma (LINNAEUS, 1758) and M. (Lyroderma) lyra PETERS, 1872. Megademza richardsi n. sp. is one of the smallest megademiatids known. It exhibits a mixture of plesiomorphic and autapomorphic features, the latter appearing to exclude it from being ancestral to any living megadermatid. The new species is one of eight megadermatids identified from the Australian fossil record, most of which are referable to Macroderma MILLER, 1906. 

Some new material of percrocutas from the late Miocene of Axios valley (Macedonia, Greece) is studied. They have been found in the locality of "Pentalophos 1" (PNT). The material has been described and compared with the known late Miocene percrocutas of Eurasia. This comparison indicates that it can be identified as Dinocrocuta gigantea (SCHLOSSER, 1903). A maxilla of a percrocuta, named ”Hyaena" salonicae, was found in the same area (Andrews, 1918). "Hyaena" salonicae is smaller than the PNT material. It is also compared with other material from Eurasia while its taxonomic and age problems are discussed. It belongs to Dinocrocuta and shows close relationships with D. robusta and D. senyureki; its age can be considered as late Vallesian-early Turolian. The age of the locality PNT is also discussed and a possible Vallesian age is proposed for it. 

A new genus and species of haplobunodontid artiodactyl, Hallebune krumbiegeli nov. gen. nov. sp., is described from the middle Eocene Geiseltal Fauna (Saxon-Anhalt, Germany). Its stratigraphic range is restricted to the MP 13 ("obere Mittelkohle") of the Geiseltalian. The material consists of seven fragments, representing both upper and lower jaws. It is indicated, that H. krumbiegeli was a small bunodont herbivore. The size and primitive character of the teeth suggest that the genus possibly is directly derived from Diacodexeidae.The new material forms the basis for reinterpreting the haplobunodontid phylogeny. 

Revision of ancient collections and study of new material from Provenchères-sur-Meuse (Rhaetian) lead to signíficant changes in the faunal list of this site. This bring to us important information about the effect of the rhaetian transgression on the evolution of the faunas at this period of time. However, study of
vertebrate microremains is always difficult and some points remain obscure, like the origin of the prosauropods which yield some remains at Provenchères-sur-Meuse and the survival in Europe during the Rhaetian of temnospondyl arnphibians different from the Plagiosauridae.

  

A new European rodent from the middle Eocene of Spain, Zamoramys extraneus n. gen., n. sp., appears to be closely related to the middle Eocene chapattimyid rodents of Indo-Pakistan. This contradicts the generally accepted paleobiogeographic hypothesis of a Tethyian barrier between Europe and Asia isolating Europe during the middle Eocene. Because of this barrier, some authors have proposed that European and Asian rodents were not closely related, their similarity being the result of morphological convergence. Here monophyly has been tested, using the parsimony criterion, based on an analysis of dental characters (including discussing of homology and the validity of some characteristics). Our results indicate a phylogenetic relationship among the Asiatic Ctenodactyloidea, Zamoramys from Spain, and the European endemic Theridomyoidea. We also conclude from our analysis that theridomyoids and European ischyromyoids are probably not closely related phylogenetically. 

A new hypothesis for the phylogenetic relationships of recent anomalurids and graphiurids is proposed, based on information from evolutionary lineages of Paleogene European rodents, particularly Gliridae, and Eocene Algerian Zegdoumyidae. Differences in first occurrences, in paleogeography, and in infraorbital structure in glirids (protrogomorphy and pseudomyomorphy) and graphiurids (hystricomorphy) separate Graphiuridae from Gliridae (Graphiurinae is here raised to family rank). Similar considerations, and dental morphology, suggest that Anomaluridae (appearing in the late Eocene) and Graphiuridae (appearing in the Pliocene) are related to early Eocene Zegdoumyidae. 

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

Dichobunoid artiodactyls are described in this paper from the middle Eocene Geiseltal lignite deposits near Halle (Sachsen-Anhalt, Germany). The genera Eurodexis and Parahexacodus are established based on odontologica1 studies. The type-species are E. ceciliensis (FRANZEN & KRUMBIEGEL, 1981) and P. germanicus n. sp. from the "obere Mittelkohle" (see text), MP 13. The genera are referred to the new subfamily Eurodexeinae (Dichobunidae, Artiodactyla, Mammalia), which also contains the monospecific genus Eygalayodon SUDRE & MARANDAT, 1993. These new genera show many features similar to North American homacodontids and antiacodontids. They exemplify a high degree of diversity in European dichobunids. Moreover, the family Dichobunidae includes the Dichobuninae and the Hyperdichobuninae. The connection of the posthypocristid with the postentocristid, the shift of a medial to a lingual position of the hypoconulid on the lower molars and the development of a large, caniniform P1 are regarded as the principal tendencies of the eurodexeines. The entoconid is larger and more mesially situated compared to that of Diacodexis. The hypoconulid has a lingual position on a broad postcingulid. The elongation of the premolars and the presence of diastemata are considered associated with extension of the muzzle. This and the acute tubercles of the molars could indicate a limited degree of insectivory. Protodichobune cf. oweni and Diacodexis cf. varleli, first reported here from the "untere Unterkohle" (MP 11) of the Geiseltal, demonstrate the existence of forms in the basal part of the middle Eocene, that are direct descendants of lower Eocene ones. Eurodexis russelli n. sp. from MP 10 of Premontre is the most primitive representative of Eurodexis. A further part of this lineage could be Messelobunodon sp. from MP 11 of Messel (Germany). Another form from Premontre, referred to Eurodexeinae indet., represents the origin of the lineage to Parahexacodus germanicus n. sp. from the Geiseltal (MP 13). The identification of several lineages in MP 10 is evidence of an adaptive radiation during this time. Unfortunately the history of the earlier species of Diacodexis is not known well enough to exclude earlier diversifications. Our study shows the independent development of artiodactyls at the end of the lower Eocene in Europe, North America (and maybe in Asia) with much convergence. The question of the geographic origin of the genus Diacodexis is still open. 

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

An interpretation of the marine reptile fossil record, based on the existing litterature and complemented by the review of ancient collections and the study of new material, permits a better understanding of Mesozoic marine ecosystems. An inventory of the marine reptiles known from the Lower Triassic to the Paleocene is presented: 46 families, about 200 genera and 400 species have been recorded. This data base includes commentaries about systematics, stratigraphical ranges and geographical distribution of taxa. Marine reptiles include a mosaic of not necessarily closely related groups: ichthyosaurs, thalattosaurs, hupehsuchians, pachypleurosaurs, placodonts, nothosaurs, plesiosaurs, pliosaurs but also crocodiles, lizards, snakes, turtles. The diversity studies reveal that the fossil record of marine reptiles has been punctuated by two mass extinctions, during the Middle-Upper Triassic transition and at the Cretaceous-Tertiary boundary. The Jurassic-Cretaceous and Cenomanian-Turonian boundaries (the latter marked by the disappearance of ichthyosaurs) are potential crisis periods, but current data are not sufficient to reach conclusions. The Ladinian-Carnian transition is characterized by the disappearance of 64 % of families and affects essentially coastal forms. This extinction coincides with an important regressive phase. During the Upper Triassic, a faunal reorganisation within marine reptiles leads to the progressive disappearance of near-shore forms and to the development of pelagic groups. During the Maastrichtian-Danian crisis, 36% of families died out. Large-sized pelagic forms such as mosasaurs and elasmosaurs were the most affected and their extinction seems to have been rather sudden. On the other hand, pliosaurs and protostegid turtles became extinct, but were already declining. The survivors were near-shore forms such as crocodiles, snakes and some turtles and they may have taken refuge in freshwater environments. A break in the food chain based on phytoplankton is proposed as an extinction scenario for pelagic forms.