斯氏黄河猴(哺乳动物纲,灵长目)较完整下颌骨的发现

新发现的下颌骨说明斯氏黄河猴下齿式为 ２？, １,３, ３。 ｐ２为双根齿,其前后有短的齿隙;ｐ３具有低小的后跟;ｐ４未臼齿化,无下前尖,有初始的下后尖,在较大的跟盆上,有明显的下次尖和很小的下内尖？; ｍ１下前尖小,有些前后收缩（与Ｒｅｎｃｕｎｉｕｓ ｚｈｏｗｉ比较）,ｍ３下次小尖不如正模发育。下颌骨联合部倾斜,不愈合。黄河猴的下臼齿在形态上与西瓦兔猴亚科和原始类人猿──渐新猿亚科有许多共同点,但上臼齿形态差异显著。黄河猴类可能出自亚洲的ｃｅｒｃａｍｏｎｉｉｎｅ形的兔猴形灵长类。

DISCOVERY OF A NEARLY COMPLETE LOWER JAW OF HOANGHONIUS STEHLINI ZDANSKY, 1930 (MAMMALIA,PUIMATES)

Hoanghonius found in the "River section" of Yuanqu Basin, Shanxi Province is the earliest discovered Eocene Primates of China. The materials are a fragmentary lower jaw with only two lower molars on it and an isolated upper molar. For above specimens Zdansky (1930) named as Hoanghonius stehlini and pointed out that the lower cheek teeth of this animal resembled those of notharctids while the upper molar was similar to omomyids, so the systematic position of Hoanghonius was Primates incertae sedis. Later on Hoanghonius was placed in Omomyidae (Hill, 1955; Woo and Chow, 1957; Romer, 1966). But in the past twenty years it was normally placed to Adapidae (Szalay, 1974; Gingerich. 1976; 1977; Rasmussen and Simons, 1988). Someone, however, thought it to be related to living cheirogleids of Madagasga (Schwartz, 1986). Owing to some similarities in lower cheek teeth between Hoanghonius and earlier anthropoids-- Oligopithecus, some people believed that Hoanghonius might have something to do with origin of anthropoids. Why the systematic position of Hoanghonius is so different? The main reason is no complete materials have been found. In the past five years we worked in Yuanqu Basin and found precious Eosiamis as well,as many other mammalian fossils, including incomplete lower jaws and isolated teeth of Hoanghonius. Fortunately we discovered a rather complete lower jaw of Hoanghonius in the recent field work, which is the best specimen ever found since it has been created. This specimen not only provides many new morphological information but also is useful for determining Hoanghonius' systematic position and its relationships with early anthropoids.