山西天镇后裂爪兽属(哺乳动物纲,蹄兔目)化石初步报道

山西天镇的蹄兔化石被定为Ｐｏｓｔｓｃｈｉｚｏｔｈｅｒｉｕｍｉｎｔｅｒｍｅｄｉｕｍ。这是该属目前所知最好的一批材料,使我们对该属头骨、下颌和牙齿的特征有了更多、更确切的了解。该属头骨吻部拉长变宽,门齿间有长的齿隙;头骨和下颌骨具多个凹陷;上臼齿单面高冠,白垩质发育。这些特征足以把它和所有其他相近的属区别开来。后裂爪兽属似有明显的雌、雄性差异,主要表现在个体大小和门齿的形态及粗壮程度上。天镇产后裂爪兽化石地层的地质时代,根据蹄兔化石的进化水平和整个动物群性质判断,比泥河湾典型层位要早,可能应在１。８Ｍａ~２．６Ｍａ之间。

PRELIMINARY REPORT ON POSTSCHIZOTHERIUM (MAMMALIA:HYARCOIDEA) MATERIAL FROM TIANZHEN, SHANXI, CHINA

The hyracoid material discovered from a small basin of the Tianzhen County, Shanxi Province, by Wei Qi and Chen Zheying in the early 1980s, comprises at least five partially preserved skullsand lower jaws and a number of isolated teeth. It is here identified as belonging to Postschizotherium intermedium . This is the largest sample so far known of the genus Postschizotherium. It considerably enhanced our understanding of the morphology and affinity of the genus. The present paper describes only the most representative specimens of the sample: an anterior part of skull with its lower jaw of old male individual (V 6825) and a palate with its lower jaw of juvenile female individual (V 6826) . The study of the total material will be published elsewhere.