湖南对锥齿兽科(Didymoconidae)一新属及有关地层的讨论

湘掠兽是我国下始新统中新发现的一种对锥齿兽类,与北美早始新世怀俄明兽(Wyolestes)比较相近。依形态和共生动物群的分析,其时代可能是早始新世早期。从有关剖面观察和追溯,其层位大致相当于栗木坪组。根据我国地层规范的规定,原岭茶组一名应予放弃,建议仍使用栗木坪组一名,以示衡阳盆地含哺乳动物化石的层位。

A NEW DIDYMOCONID (MAMMALIA) FROM THE EARLY EOCENE OF HUNAN

An incomplete didymoeonid skull from Lingeha, Hengyang Basin, where C. C. Young found the first fossil vertebrate in Hunan Province, is here described as a new genus and species-Hsiangolestes youngi (Family Didymoconidae). The family includes two subfamilies: Didymoconinae and Wyolestinae according to Gingerich (1981). Hsiangolestes is similar to Wyolestes in having full upper dental formula and in general tooth structure, and thus assigned to the subfamily Wyolestinae. It differs from the American genus by relative small size, in haying less developed anterior and posterior cuspules on P~3, wider first two upper molars with larger conules and more prominent eingula. Associated with Hsiangolestes, in Eocene beds of the same Basin vertebrate fossils like those of Archaeolambda,?Asiocoryphodon, Matutinia, Hunanictis, Cocomys and Propachynolophus as well as some invertebrates have been reported by Young, Li and the others, demonstrating that the age of the mammal-bearing beds is of Early Eocene, probably the earliest. The name Limoping Formation is chosen for the beds as it was proposed and first came into use.