中国的脊棱齿象属(Stegolophodon)化石

剑齿象属 Stegodon 起源于脊棱齿象属 Stegolophodon,两者都是亚洲大陆晚新生代的特有动物,本文讨论两属中一些种的性质和分类位置问题,并记述了药铺脊棱齿象 Stegolophodon officinalis 的新材料.

OCCURRENCE OF PROBOSCIDEAN GENUS STEGOLOPHODON IN CHINA

Stegolophodon is a purely Asiatic genus. There are 12 species of the genus and half of the 12 species were present in China. It appeared for the first time in the Middle Miocene of Jiangsu (Chow, 1959). It flourished in the Pliocene time and is found in the deposits of Yunnan (Chow et Zhai, 1962; Liu et al., 1973; Tang et al., 1974; Yun-bo, 1975; Jiang et al., 1983; Zong, 1991), Shanxi (Schlosser, 1903; Young, C. C., 1935; Teilhard et Trassaert, 1937), and Sichuan? (Hopwood, 1935). Based on recent studies of the dental morphology (mainly M_3) of the fossil elephant material from the chinese Neogene, the Stegodon zhaotongensis (Cnow et Zhai, 1962), the Stegodon baoshanensis (Yun-bo, 1975), the Stegodon officinalis (HoPwood, 1935), the Stegodon licenti (Teilhard et Trassaert, 1937), and the Rulengchia hueiheensis (Chow, 1959) was assigned to the genus Stegolophodon. Present author placed Stegodon baoshanensis as well as the Stegodon zhaotongensis under the synonymy of the Stegolophodon officinalis, distinguishing the latter from the known South-Asiatic species on the bases of its median cleft present at first three ridge-plates and no accessory tubercles or conules in the intermediate valley. In addition, a species known from the Middle Miocene Xiacaowan Formation of Northern Jiangsu described by Chow (1959) as Stegolopht'on hueiheensis and later on as Rulengchia hueiheensis by the same author(1983) is regarded the genus Stegolophodon. Because the molar (M_3) with four ridge-plates and a small tylon shows ery low crowned, each ridge-plate with six (or less) low rounded conical cusps, median cleft p esent at the first three ridgeplates and the superior tusks with a thin and narrow enamel band character, etc. of the genus Stegolophodon.