陕西洛南人牙化石及其地质时代

在陕西省洛南县洛河左岸洞穴中,发现一古人类上臼齿,其特点与郧县人牙化石很相似。与人牙化石共存的有大熊猫和獏。后二者比华南洞穴中常见的同类化石明显小,比广西柳城巨猿洞中的小型者要大。从化石特点分析,洛南人牙化石及其所在沉积层的时代为中更新世早期(也有早更新世晚期的可能)。

HUMAN FOSSIL TOOTH FROM LUONAN, SHAANXI, AND ITS GEOLOGICAL AGE

A right Ml of human fossil, associated with a left M1 of Ailuropoda and a right M1 (or M2) of Tapirus, were collected from Qinling Mountains. The exact locality of these fossils is on the hill slope behind the Donghe village, Luonan county, Shaanxi Province.The human fossil tooth is larger than that of modern man, and also larger than the ave-rage size of Peking Man, but quite similar to those of Hexian Man, Yunxian Man and Java Man. It possesses the vertical furrows on both lingual and buccal surfaces. The shape of the crown is about rhomboid and has an obvious medial lingual angle. There are a couple of ridges on the slope of each cone. Judging from its morphology and size, Luonan tooth probably be-longs to that of Homo erectus.Except the size, the tooth of Ailuropoda is even less likely to be distinguished from those of common panda on its characteristics. The size of the tooth of Luonan Ailuropoda is much smaller than that of A. melanoleus baconi, distributing widely in the Middle and Late Pleisto-cene of southern China and larger than that of A. microta, a small type of Early Pleistocene, but rather similar to that of A. m. favealis of late Early Pleistocene or modern panda. Owing to its deeper petrification and associated with primitive human fossil, the panda fossil of Luo-nan would rather belong to A. m. favealis than modern one.According to the fossil evidence and the stage of human evolution, the geological age of these fossils from Luonan may be early Middle Pleistocene or Late Early Pleistocene.