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

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. 

New dental and skeletal material referable to Palaeochiropteryx tupaiodon from the Middle Eocene locality of
Messel (G.F.R.) is studied, which provides additions to the previously gained knowledge of this european genus. Dental specimens from Geiseltal (G.D.R.), also of Middle Eocene age, allow us to analyze Cecilionycteria prisca. Some of these are separated to establish a new genus, Matthesia, and two new species, M. germanica and M. ? insolita. 

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.
  

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. 

Abstract not available 

Extensive collecting in previously known and new Middle Eocene rodent localities in the Subathu Group of the Rajauri and Reasi districts, Jammu and Kashmir (northwest Himalaya, India) has yielded over 500 isolated cheek teeth, numerous incisors and cheek tooth fragments, and two mandibular fragments with M/1-M/3. An analysis of this additional material and a restudy of that reported earlier from the Metka (Rajauri) area has revealed the presence of diverse Middle Eocene ctenodactyloid rodents in India. The assemblage comprises six genera and twelve species, viz.., Bírbalomys woodi, B. ibrahimshahi, B. sondaari, Basalomys vandermeuleni, B. ijlsti, B. lavocati, Chapattimys wilsoni, C. debruijni, Gumbatomys asifi, cf. Advenimus bohlini, cf. Petrokoslovia sp. indet. 1 and cf. Petrokoslovia sp. indet. 2. Most species of this assemblage are endemic to the Indian subcontinent and are referred to the Family Chapattimyidae. However, at least three taxa, viz.., cf. Advenimus bohlini, cf. Petrokoslovia sp.indet. 1 and cf. Pezrokoslovia sp. indet. 2 show close affinities with their Central and Eastern Asiatic contemporaries and are attributed to the Family Yuomyidae. The dentitions of most of the Middle Eocene rodents from India are described here in better detail thus providing more precise characterization than was available earlier. The taxonomie status of Basalomys, formerly a subgenus of Birbalomys has been raised to that of a genus. Basalomys vandermeuleni is here designated as the type species of Basalomys in place of B. ijlsti. The rodent assemblage from the Subathu Group is specifically similar to that from the coeval Kuldana Formation of Pakistan. The absence of Birbalomys ibrahimshahi and cf. Advenimus bohlini in Pakistan is related to sampling bias. The identifications of the Early Eocene rodents from Barbara Banda, Pakistan have been reexamined and the familial assignments of some of the Early and Middle Eocene rodents from Central and Eastern Asia have been discussed and reviewed in the light of recent discovery of early rodents in Mongolia.

  

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. 

About the early radiation of Rodents, we have now from the early tertiary of Asia, a new fossil record, and
we can do new interpretations. First the problem of the origin of Rodents is studied : considered as a sister group of Lagomorpha, it is possible to find their ancestors between the Mixodontia. Second the new facts about the origin of modern groups of Rodents are reviewed. A general scheme of this diversification can be proposed. 

Micro-CT imaging is an increasingly popular method in paleontology giving access to internal structures with a high resolution and without destroying precious specimens. However, its potential for the study of hypoplasia defects has only recently been investigated. Here, we propose a preliminary study to test whether hypoplastic defects can be detected with micro-CT (μCT) scan and we assess the costs and benefits of using this method instead of naked eye. To do so, we studied 13 fossil rhinocerotid teeth bearing hypoplasia from Béon 1 (late early Miocene, Southwestern France) as positive control and 11 teeth of the amynodontid Cadurcotherium (Oligocene, Phosphorites du Quercy, Southwestern France), for which enamel was partly or totally obscured by cement. We showed that all macroscopically-spotted defects were retrieved on 3D reconstructions and selected virtual slices. We also detected additional defects using μCT scan compared to naked eye identification. The number of defects detected using μCT was greater in the Cadurcotherium dataset (paired-sample Wilcoxon test, p-value = 0.02724) but not for our control sample (paired-sample Wilcoxon test, p-value = 0.1171). Moreover, it allowed for measuring width and depth of the defects on virtual slices (sometimes linked to stress duration and severity, respectively), which we could not do macroscopically. As μCT imaging is both expensive and time consuming while not drastically improving the results, we recommend a moderate and thoughtful use of this method for hypoplasia investigations, restricted for instance to teeth for which enamel surface is obscured (presence of cement, uncomplete preparation, or unerupted germs). 

Until now Aplodontidae of the European Oligocene have been documented by four species only. The phylogenetic relations remained obscure. as the distribution of only one species has been known in some detail. New material made it possible to define the stratigraphic range of two of the already existing species (Plesispermophilus angustidens, Sciurodon cadurcense) and to follow their development during the Oligocene beginning with the event of the « Grande Coupure ››. Sciurodon remained nearly without change until the end of the Middle Oligocene. Plesispermophilus angustidens split into two distinct phyletic lines, one of which (P. macrodon n. sp.) reaching considerable size, is represented till the beginning of the Upper Oligocene (Pech de Fraysse, Gaimersheim). The other line leads to Plesispermophilus ernii (basal Upper Oligocene of Burgmagerbein 1. terminal Upper Oligocene of Coderet). Besides the already known forms a new small-sized species (P. atavus n. sp.) is described, which by its primitive features closely resembles the genus Plesispermophilus. Two other small-sized species already known from the Upper Oligocene (? P. argoviensis) and Lower Miocene (? P. descedens) seem to be closely related to the new species. It cannot be decided whether they are descendents of this line or have developed independently, because of their poor fossil record.
Comparison of the evolutionary modalities in the different phylogenetic lines reveals general trends. the most striking of which is the complication of the tooth pattern by the development of additional crests. In the lower molars the cusps diminuate in size and are more and more transformed into ridges. ln addition new connection between the crests appear. in the upper molars, the « selenodont » shape of the teeth becomes more and more dominant, and in the two main evolutionary lines of Plesispermophilus the metaconulus becomes duplicated. A further evolutionary trend is the size increase of the premolars compared to the molars, which is even more pronounced in the Miocene Aplodontidae.
Phylogenetic relations between the primitive Plesispermophilus and certain « prociurines ›› of Northern America as well as between Plesispermophilus (P. angustidens) and more progressive forms of the Upper Oligocene (P. ernii, P. macrodon n. sp.) can be documented. In this light, the taxonomic distinction between Prosciurinae (bunodont) and Allomyinae (selenodont) sensu Rensberger 1976 can be shown to be artificial, because it separates forms from each other, which are evidently closely related. Consequently the separation into two subfamilies has been abolished. 

Le présent volume est l'aboutissement d'un projet né il y a presque cinq ans. En décembre 1991, l'un d'entre nous (MG) prenait des contacts en vue de proposer un symposium sur les mammifères fossiles, dédié à D.E. Russell, dans le programme du 4e Congrès de la European Society for Evolutionary Biology. Ce congrès, baptisé "Evolution 93", devait se tenir à Montpellier en août 1993. Son Comité d'Organisation, animé par F. Catzeflis, recherchait des organisateurs de symposiums. L'idée fut acceptée avec enthousiasme par le second d'entre nous (PDG), et le titre de notre Symposium fut précisé: " Palaeobiology and Evolution of Early Cenozoic Mammals - A Symposium in Honor of D.E. Russell". Le projet fut formellement accepté par le Comité d'Organisation en avril 1992. 

Study of pantolestid mammals from the late Ypresian locality of Prémontré (reference level MP 10) allows the recognition of three genera: Palaeosinopa. Pantolestes and Premontrelestes n. gen. Pantolestes, up to now only recorded from North America, is represented by P. sabatieri n. sp. Premontrelestes n. gen., represented by the type species P. duchaussoisi n. sp., is compared with Pantolestes and Buxolestes. The latter, known from middle Eocene sites in Europe, has not been recognized at Prémontré. Two other taxa, the first of which is close to Pantolestes and the second of Premontrelestes n. gen. are left in open nomenclature.    

Abstract not available 

Two species lineages of North American late Paleocene Plesiadapis exhibit a pattern of size divergence from a common ancestral lineage. Time series of fossils in each of these lineages are analyzed to test the idea that size divergence represents competitive character displacement. The critical factor in a test of character divergence is showing that divergent lineages evolved directionally rather than randomly (multifactorially). Analysis of evolutionary rates and their temporal scaling in Plesiadapis shows that both divergent species lineages have the scaling slope expected for lineages evolving randomly rather than directionally, and size divergence in Plesíadapis does not represent character displacement. Rates of evolution commonly observed on a per-generation time scale are high enough to produce character displacement within a few generations. Thus character displacement is not likely to be visible on scales of time that can be studied in the fossil record. 

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. 

This paper is an English concentrate of various Russian publications by the senior author presenting the mammaIian taxa from the Cretaceous (Albian through Santonian) of the region termed Middle Asia by Soviet geographers. The diagnoses are the unmodified, literal translation of the original version, but are followed with short complementary remarks; most of the species are illuslrated anew with SEM photographs, others are by normal photography. The fossiliferous formations are cited and arguments for their dating are given. Finally, the main vertebrate groups accompanying mammaIs are listed and the environment and climate at the time of deposition are suggested. In conclusion, an hypothesis on the origin and high diversity of tribosphenic mammals on the Cretaceous coastal plains of southwest Asia is proposed. In appendix the taxon Khuduklestes bohlini novo gen. novo sp. is formally defined. 

Remarkable association of a small infraorbital foramen, similar to that in recent Heterocephalus, and of a strong muscular print on the dorsal anterior part of the zygomatic plate and on the premaxillary. Several anatomical structures to be compared with those of Heterocephalus suggest relationships with this genus. Richardus supports the ancestrality of the hystricomorph character in the bathyergids 

Crocodilians are represented in the Upper Eocene of Sainte·Néboule (Lot) by an isolated parietal and a dorsal scute, bath from young individuals. They are refferred to Diplocynodon sp. Predators (mammals and birds) are probably responsible for the occurrence of remains of small crocodilians (belonging to the genera Allognathosuchus and Diplocynodon) in the phosphorltes of Quercy. 

The new fauna of Collet Redon (Bouches-du-Rhône, France) is dated by three rodents: Megacricetodon aff. bavaricus, Democricetodon affinis mutilus and Peridyromys cf. hamadryas. They correlate this locality with Oggenhof and Ohningen in Bavaria (Western Germany). As the radiometric age of Ohningen is estimated between 14 and 13 M.Y., these three localities are of Serravallian age. This datation brings a complete readjusment of the stratigraphy of the section of Collet Redon formerly described by Collot and Combaluzier. The marine deposits with underly the continental formation with the mammal fauna, are Burdigalian. The angular unconformity between the marine and the continental deposits gives evidence of an episode of emersion on the margin of a sedimentary basin, with deformation and erosion. Owing to the newly discovered fauna, this geodynamical event is clearly settled within the regional geographical and chronological context. Lacustrine and continental deposits of such an age were up to now unsuspected in this area.