摘要：The occurrence of upper Eocene mammals in Guangsi was first reported by Chow in 1957. Since then, more mammalian fossils of this age have been discovered, among these fossil mammals. Some condylarths are known from four localities in Baise and Yongle Basin. All specimens described in the present paper came from the Nado Formation, which is generally considered as of the latest Eocene in age.
The fossil material consists of the following forms:
Phenacodontidae, Eodesmatodon spanios gen. et sp. nov.
Mesonychyidae, Guilestes acares gen. et sp. nov.
Guilestes cf. acares
cf. Harpagolestes sp.
Eodesmatodon resembles Desmatoclaenus in general shape of inferior molars, but is clearly different from all known genera of Phenacodontid in having a simple P4, bigger M2 and a relatively reduced M3. Guilestes is of the same size as Dissacus and Lestes, but is characterized by the lacking of any trace of a metaconid on trigonids of the lower molars and loss of M2.
The discovery of Phanacodontid Condylarthra is the first definite record of this group from the Eocene horizons in Asia and this form represents the last survivals of the group beyond middle Eocene.