In dilambdodont molars the primitive crest between paracone and metacone (centrocrista) is represented by a pair of crests that join the mesostyle (postparacrista, premetacrista). The cutting action of these crests against the crests of the hypoconid is described. Dilambdodonty is a derived adaptation for greater cutting efficiency. It has evolved several times and in more than one way. 

The composition of assemblages of lizards and Amphisbaenian from the European Eocene are described. At least ten lizard families are identified from the lower European Eocene levels. Eight are still recorded in the last level (Escamps) of the late Eocene. Agamid lizards (genus Tinosaurus) died out by the end of the lower Eocene and Varanid lizards (genus Saniwa) disappeared by the beginning of the late Eocene. Amphisbaenians are recorded throughout the Eocene in Europe. The lacertilian fossil record of Europe and North America show a high degree of faunal resemblance in the early Eocene, followed by a decrease during the later part of the epoch. The lacertilian and amphisbaenian faunas from the European Eocene are not subject to great variations during the period; this is in contrast with the mammal record at the same time. It is argued that the low metabolic rates and the ectothermy of lizards could explain those differences, along with the increasing insularity of the West European area during the late Eocene time.

  

The Middle Eocene Fossillägerstätte of the Geiseltal lignite beds near Halle/S. (German Democratic Republic) is the reference locality of the European land mammal age Geiseltalian and of the Mammalian Paleogene reference levels MP 11 - MP 13. Due to this importance a reinvestigation is given of the lithostratigraphical development of the Geiseltal beds and of their vertebrate sites. The last are genetically related to the southwest border of the Geiseltal depression and the influx of carbonate-rich waters. The geographical distribution and stratigraphical position of the fossiliferous sites depends on subrosive and tectonically controlled distribution of coal seams. The geological factors and the known stratigraphical guide of some mammalian species suggest corrections of the age of some sites. Four of the alltogether five coal bearing phases contain the 35 sites with mammalian remains. By the distribution of the around 69 mammal species are characterized, with 5 faunal steps ranging from MP 11 to MP 14 or over the Geiseltalian up to the Lower Robiacian. Well distant are the faunas of MP 11 and MP 12. Beginning with MP 12 up to MP 13/14, the fossil record is very frequent by 27 sites. This evidence coincides somewhat more with the concept of land mammal ages compared to that of the punctual mammalian reference levels. 

New records of terrestrial mammals from the Qasr el Sagha Formation, Fayum Depression, Egypt are reported, and the stratigraphic occurrences of these fossils noted. These include additional specimens of Moeritheríum, Barytherium, and anthracotheres, as well as the oldest record of a hyracoid in the Fayum.These Eocene mammals occur almost exclusively in the alluvial deposits of the Dir Abu Lifa Member of the Qasr el Sagha Formation and show close affinities to the faunas from the lower sequence of the Jebel Qatrani Formation. There is no evidence of a more marked faunal discontinuity between the Qasr el Sagha and Jebel Qatrani Formations than there is across any of the three major breaks in sedimentation that exist within the Jebel Qatrani Formation. The faunal similarities between fossils of the lower sequence of the Jebel Qatrani Formation and of the upper part of the Qasr el Sagha Formation is consistent with recent paleomagnetic dating that suggests that these rocks differ in age by only one to two million years. 

La taphonomie (science de l'enfouissement et de la fossilisation) des micromammifères a trop souvent été négligée par rapport à celle des grands mammifères. Or, pour expliquer les concentrations parfois très importantes de microfossiles dans les grottes et les sites préhistoriques il faut connaître les mécanismes qui concourrent actuellement à favoriser les accumulations de ces derniers. C'est le but de l'ouvrage de Peter Andrews qui se décompose en deux parties.