New Dendromus species (Rodentia, Muroídea) from Langebaanweg (Pliocene, South Africa). Stratigraphical and paleoecological consequences.

Two new species of Dendromus are described from the Langebaanweg site which precises the evolutionary trend among this genus in South Africa and gives further paleoenvironmental indications. Two evolutionary stages are described: D. darti nov. sp. shows low-crowned molars with bunodont cusps and its more closest relative would be D. melanozis from the Cape region. On the contrary, D. averyi nov. sp. is more lophodont and is better related with the modem D. melanotis. Both species are at a less evolved stage than the Dendromus sp. from Laetolil Beds at Laetoli. The Langebaanweg deposits cannot still be dated by biostratigraphy but they clearly cannot be older than the basis of Pliocene times. The association of Dendromus and Mystromys in the same levels indicates a grassland environment with woodland patches as well as probable swamps. 

The two species of Sandgrouse from Quercy, Pterocles validus MILNE-EDWARDS and P. larvatus MILNE-EDWARDS, are ascribed to the genus Archaeoganga MOURER-CI-IAUVIRÉ which includes a third, very large species, A. pinguis. The sandgrouse of Saint-Gérand-le-Puy, Pterocles sepultus MILNE-EDWARDS, is ascribed to a new genus, Lepzoganga. This form appears in the Upper Oligocene of Quercy, in Pech Desse and Pech du Fraysse localities, and is still present in the Lower Miocene of Saint-Gérand-le-Puy and Paulhiac. Recent sandgrouse live in semidesert or desert areas. The indications provided by mammal and bird faunas in the localities where sandgrouse were found, confirm that the paleoenvironment was open and arid. The morphological study of these fossils indicates that, in the Upper Eocene, the Pteroclidae were already completely individualized with respect to Charadriiformes.
  

In the course of the current revision of adapid primates from the Eocene Geiseltal, an almost complete specimen was found in the Geiseltal Museum collections. The fossil, the most complete adapid specimen so far discovered in Europe, has been determined as Pronycticebus neglectus n. sp.
Ecology and locomotion as well as the likely phylogenetic position within the infraorder Adapiformes are discussed. 

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

The Montredon site has yielded about hundred rhinoceros remains:
- twenty two of them, including 14 carpal and tarsal bones and 6 complete metapodials, belong to
Dicerorhinus schleiermacheri at its second evolutionary stage;
- fifty one remains including a nearby complete but crushed skull, a mandible, 26 isolated cheek-teeth, 10 carpals and tarsals, one metacarpal, are of Aceratherium incisivum, second evolutionary
stage;
- fifteen remains belong to Aceratherium (Alicornops) simorrense (among other an upper molar, 8 carpals and tarsals, one metatarsal);
- six remains are attributed to an undetermined species of what is probably the most recent Prosantorhinus ever found.
The evolution stages of the two first species allow us to date the deposit back to the Upper Vallesian, MN 10 zone; Montredon is one of the youngest sites in which Aceratherium simorrense was found. The four rhino species indicate a swampy forest biotope 

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.