Afin d'étudier la magnétostratigraphie de la colline de Montredon, j'ai prélevé en Avril 1982, 93 carottes orientées réparties sur 29 sites. J.-P. Aguilar et I. Loridant m'ont aidé durant cette opération. Pour la stratigraphie de la coupe échantillonnée et pour le contenu faunique des deux gisements de mammifères de cette colline, voir J.-P. Aguilar & J.-Y. Crochet (1982).
[...] 

Le Mémoire Extraordinaire 1988 de PALAEOVERTEBRATA regroupe dix articles consacrés au gisement à mammifères du Miocène supérieur de Montredon (Hérault), connu et classique depuis la fin du siècle dernier, et auquel est lié le nom du savant paléontologue lyonnais Charles Depéret.
Cette monographie vient normalement à la suite de celle parue en 1982 dans PALAEOVERTEBRATA, dont les différents articles traitaient de la stratigraphie du gisement, et faisaient l'étude des différents groupes de micromammifères représentés dans la faune (insectivores, chiroptères, rongeurs). 

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.
  

The utilization of screen-washing and attack by dilute acetic acid has permitted the collecting, in the Miocene of the department of Hérault (France), of a very rich ichthyofauna. This fauna is presently comprised of about 60 studied species, of which 11 are new, and represents, in the present state of knowledge, the most varied Miocene selachian fauna described in the world.
The abondance of material has allowed an overall revision to be made; it has thus been possible to complete the description and the figuration of species that were poorly known until now, and to synonymize species that were established on simple morphotypes. Paleo-ecologic study of the ichthyofauna has permitted conclusions to be drawn relative to climate and bathymetry; it was thus possible to show that the Miocene fauna of Hérault was a fauna of a subtropical sea, essentially neritic with rare pelagic contributions.
Knowing the stratigraphic position of the localities, it has been possible to distinguish three faunal assemblages based on associations of species. Some hypotheses on the evolution of certain lineages have been expressed.
The comparison of this fauna with that of other regions permitted the relationships of two diflerent faunal provinces to be specified: the first belongs to the northern domain, characterized by a fauna still subtropical but with numerous temperate water elements; the leoond belongs to the Mesogean domain characterized by warm water forms. It has also lhovm that contemporary faunas could be very different according to the bathymetric zone in which they lived, which furnishes valuable information for the paleogeographic reconstruction of sedimentary basins.
  

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. 

The knowledge of the Anchilophini has been lately renewed by the discovery of a rather large amount of new material still largely unpublished. This new material offers the opportunity of a systematic revision of this tribe gathering those of European Eocene Equoidea which bear no mesostyle on upper check teeth and display a heavy trend to the molarization of premolars.

A cladistic analysis has made out two genera, Anchilophus (Paranchilophus included as a subgenus), characterized by a marked lophodonty and the transverse narrowness of the cheek teeth, a rather high hypsodonty, the frequent occurrence of "crochets" and "anticrochets" on the superior ones, and a rather weak molarization of the premolars, opposite to Metanchilophus n. gen. whose cheek teeth are more transversally elongated, less high, less lophodont, with cusps better distinct, enamel thicker and premolars more molarized on the whole.

Three species of Anchilophus are recognized, A. desmaresti, type species of the genus, A. (Paranchilophus) remyi and A. (Paranchilophus) jeanteli n. sp.

The genus Metanchilophus is more diversified with the species dumasi, radegondensis, gaudini (whose a new sub-species M. g. fontensis is defined), depereli, castrensis n. sp. and chaubeti n. sp.

The skull anatomy has been moreover described with several taxa; it brings to light (for all that one can generalize) that Anchilophini were light animals with a slender and elongated snout, a thin zygomatic arch, a rather developed encephalon with an advanced gyrencephaly.

The structure of the nasal opening together with the occurrence of epitympanic sinuses and the molarizing process of the premolars corroborate the attribution of this tribe to the family PalaeotheIiidae. 

Aside from Madtsoiidae, anilioids, and Boidae that were studied previously, the middle Palaeocene of ltaborai (BraziI) has produced Ungaliophiinae ("tropidophiids"), booid-grade snakes incertae sedis, and a possible Russellophiidae (Caenophidia) that are described in the present article. This article is the third and final report on the snakes from the locality. The Ungaliophiinae (Paraungaliophis pricei gen. et sp. nov.) are rare whereas the booid-grade snakes incertae sedis (ltaboraiophis depressus gen. et sp. nov., Paulacoutophis perplexus gen. et sp. nov.) are more frequent. A single vertebra is referred to the Russellophiidae (Caenophidia) with reservation. An update of the whole fauna of snakes from ltaborai is provided. Hechtophis austrinus that was tentatively referred to the erycine Boidae is now regarded as a Boidae incertae sedis. Most snakes from Itaborai are known only from the locality. Astonishingly, only the ailioids Coniophis cf. C. precedens gives possible evidence of interchanges between South and North America. The fauna of snakes from Itaborai, as well as the other Palaeocene faunas of snakes from South America are distinct from those of the Cretaceous and the Eocene of South America; they appear to be more different from the Cretaceous faunas than from those of the Eocene. The fauna from Itaborai is the richest and most diverse assemblage of snakes from the Palaeocene worldwide; it shares only a few taxa with other Palaeocene localities. 

The locality of Dams (Quercy, southwestern France) has yielded two fossil assemblages, one from the late Eocene and another from the early Oligocene, making it one of the few localities with infillings across the Eocene-Oligocene transition. At least 24 taxa (13 mammals, 11 snakes) have been identified in this locality. Study of the lissamphibian remains from Dams yields an Eocene and an Oligocene assemblage, with a total of eight taxa. The Eocene assemblage includes two unnamed salamandrine species, one unnamed pelobatid species and one pyxicephalid species (Thaumastosaurus). The Oligocene assemblage includes two unnamed pleurodeline species, one salamandrine species (Salamandra sansaniensis) and an unnamed pelobatid species. Among the eight taxa from Dams, one Eocene salamandrine and one Oligocene pleurodeline are identified for the first time in the Quercy. A review of the lissamphibians from the Quercy area identifies eleven taxa for the Late Eocene (MP19) and eight taxa for Early Oligocene (MP22), with a major turnover at the Eocene-Oligocene transition. This turnover occurs in a time of major climatic changes, with a significant decrease in temperature and precipitation and concurrent increase in seasonality in Europe, likely affecting specialized taxa.
  

Several different taxa of jawed vertebrates are reported for the first time from the Devonian of south-eastern Montagne Noire, France. Besides some undeterminable fragments of placoderm fishes from the Pragian and Lower Emsian, the material from the Upper Devonian is mainly represented by Melanosteus occitanus gen. and sp. nov. (Frasnian) and Thoralodus cabrieri LEHMAN, 1952 ("Famennian"). The good state of preservation of Melanosteus allows a detailed anatomical study leading to a phylogenetic analysis of the selenosteid pachyosteomorphs. 

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

The Zanclian marls from Papiol provided otoliths belonging to 53 teleost taxa; nine of those are new for the Mediterranean Pliocene. The association reflects a bathymetry between 150 and 350 m, but it is likely that such depths only existed at the initial stage of flooding of the Llobregat bay. A compilation of the available data for the whole Mediterranean realm at Zanclian time provided a list of 163 taxa, of which 105 could be identified at species level. This last group provides the most useful data for evaluating the composition and affinities of the Mediterranean Zanclian fauna, which appears to be significantly different from the Recent Mediterranean fauna. The Zanclian fauna counts 68 % of Recent species: 12,5 % were already represented in the Mediterranean Miocene, 37 % appeared there at the Zanclian, and 18 % are extra-Mediterranean today. This last group is essentially composed by oceanic fishes, living in the warm parts of the Atlantic and Indo-Pacific Oceans. It is evident that a non neglectable number of Recent species only penetrated very recently in the Mediterranean, which stresses the differences between the more oceanic Zanclian Mediterranean fauna and the present one.


  

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. 

Redécouvertes en 1968 dans le bois du Bretou, les deux poches à phosphorites qui ont livré cette faune sont parmi les plus méridionales du plateau quercynois. De faible profondeur, huit mètres, les cavités sont de petite taille et font partie d'un complexe de sept fissures réparties dans les bois du Bretou. Les autres trous n'ont livré aucun fossile, soit parce qu'ils avaient été intégralement vidés de leur sédiment, soit que des venues d'eau en interdisent l'accès.
Dans les deux poches fossilifères, proches de quelques mètres, le sédiment que l'on rencontre en placage sur les parois présente un aspect particulier. Il s'agit en effet d'une brèche très indurée, où la calcite domine, et contenant assez peu de sédiments sidérolithiques. Les ossements contenus dans cette brèche sont assez nombreux, très souvent brisés. Les dents isolées y sont relativement rares. Exploitées séparément, les deux poches ont livré des faunes identiques, aucune différence chronologique ne pouvant être décelée entre elles. Les formes rencontrées dans une seule des cavités sont rares mais la poche la plus riche est celle dénommée Le Bretou 2.
L'intérêt de la faune récoltée réside dans son ancienneté. On sait en effet que H.G. Stehlin avait signalé dans les collections du Quercy des restes attribuables à Lophiodon lautricense, mais la provenance exacte de ces fossiles reste inconnue. Au Bretou si nous n'avons pas rencontré à ce jour le Lophiodon, il n'en demeure pas moins que l'âge de la faune récoltée doit être proche de celui de la faune de Robiac. 

Deux types de remaniements post mortem me paraissent caractéristiques de l'état de conservation des dents de mammifères fossiles dans les Phosphorites du Quercy :

1) Des destructions localisées d'origine biologique, sous forme de galeries de morphologie très variable creusées dans la dentine et le cément, et impliquant sans doute la participation de différents types de micro-organismes. Ces altérations se sont développées peu de temps après la mort, avant la fossilísation proprement dite et se sont rapidement arrêtées après l'enfouissement dans le sédiment phosphaté.

2) Des perturbations dans les structures de la dentine liées aux variations locales de minéralisation, provoquées par une imprégnation diffuse des zones les moins calcifiées par divers minéraux et probablement surtout de l`apatite. 

Several endemic deer remains from the Middle Pleistocene deposits of the Castiglione cave (Oletta, Haute-Corse) are examined here. A morphometric analysis allows to relate them to a new insular subspecies Cervus elaphus rossii. The bones were compared with those of the mainland early Middle Pleistocene subspecies Cervus elaphus acoronatus Beninde and the European species Cervus elaphus Linné (Late Middle Pleistocene and Upper Pleistocene forms (continental and insular)). The Castiglione fossil shows peculiar morphofunctional features in its appendicular skeleton suggesting a morphological convergence with certain Bovidae. 

The scientific career of D.E. Russell began with a Pliocene fauna from Oregon, and then turned in the direction of European Paleogene mammals. Field work followed by study of the mammals that were collected, firstly in the Paleocene and later in the early Eocene, greatly rejuvenated learning in this field. Syntheses on the Northwest European Tertiary basin and on European marnmals and stratigraphy came next. Research on the Eocene of Asia was carried out jointly with Gingerich on Pakistan and with Dashzeveg on the faunas of Mongolia. An important synthesis on the entire Paleogene of Asia, joint with Zhai, followed. Field work in Africa with Sigogneau-Russell led to the discovery of Mesozoic mammals there. A synthesis of mammalian paleofaunas of the world was written with Savage, and a similar synthesis of Cenozoic vertebrate faunas is currently being prepared. These achievements reflect the perennial importance of field work, numerous collaborations with both amateurs and professionals, and the human qualities of this author.
  

Two steps can be distinguished in the history of the first invasion of western and south western Europe by the arvicolines. The first step corresponds to the installation of these rodents with the immigration of Promimonys inxuliferus Kowalski, then of Mimomys stehlini Kormos and of Mimomys gracilis (Kretzoi). The second is characterized by the establishment of a geographic differentiation in the arvicoline fauna between the south of France and Spain, from where are described new species of Mimomys (Mimamys cappettai, Mimomys septimanus, Mimonys medasensis), and the rest of France, where are found only elements already known from central Europe or England (Mimomys polonicus Kowalski, Mimomys pliocaenicus F. Major, Mimomys reidi Hinton, or forms very close to the latter). This geographic differentiation, which is very certainly the consequence of the division of Europe into distinct climatic provinces, one of them being the southern province comprising at least Spain and southern France, could result from a cladogenetic evolution of Mimomys stehlini and Mimomys gracilis after their immigration. The present work is also a contribution to the search for correlations between the diverse micromammal localities of the latest Pliocene (or early Villafranchian) and of the early Quaternary of Europe. 

Bulk-sampling of fossil-rich tempestites from the Chattian Sülstorf Beds of
Mecklenburg, north-eastern Germany, yielded a rich selachian fauna in which batoids
predominate by the abundance of teeth but are subordinate by the number of taxa. Thirteen
taxa are identified, among which rajiform batoids are the most diverse (six species). One
genus and three species are newly described: Raja thiedei sp. nov., Oligoraja pristina gen. et
sp. nov., and Torpedo chattica sp. nov. Two species are reallocated: Atlantoraja cecilae
(Steurbaut & Herman, 1978) new comb., and Dipturus casieri (Steurbaut & Herman, 1978)
new comb. Ontogenetic heterodonty is documented for the first time in the dental pattern of
Myliobatis sp. Stratigraphical ranges of batoid taxa in the period from Rupelian to Langhian
are presented and partly discussed in context with the palaeoclimatic evolution and
palaeogeographic situation of the North Sea Basin. 

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. 

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.