Révision des Artiodactyles de l'Eocène moyen de Lissieu (Rhône)

Jean Sudre

The object of this work is the study of the artiodactyls of the karstic locality of Lissieu near Lyon. Among the sixteen species counted, five (Hyperdichobune nobilis, Hyperdichobune sp., Haplabunodon mulleri, Tapirulus depereti and Pseudamphimeryx schlosseri) are cited for the first time in this fauna. The description of part of the anterior dentition of «Dichobune» langi permits the referal of this species to the genus Hyperdichobune. The new selenodont species Dichodon lugdunensis  described in this work belongs, with its ancestor Dichodon simplex, to a lineage distinct from that of Dichodan cartieri and Dichodon ruetimeyeri. Finally, the taxonomic reality of the Lissieu species, Lophiobunodon rhodanicum Deperet, is justified. All the other species have been compared with those of Egerkingen. Even though with most of them no difference in age can be shown between the two deposits, some however indicate clearly by their degree of evolution that Lissieu is slightly more recent than Egerkingen. ln the history of Eocene mammals, the Lissieu fauna, because of its homogeneity, can be considered as a sure reference fauna of the Auversian period.