黑犀(奇蹄目，犀科)化石在中国的首次发现

FIRST DISCOVERY OF DICEROS(PERISSODACTYLA,RHINOCEROTIDAE)IN CHINA

黑犀(Diceros属)的惟一现生代表D.bicornis生活在非洲。该属在新近纪时期曾广泛分布于希腊、土耳其和伊朗等地区,但从未在东亚地区发现过。新种甘肃黑犀(Diceros gan- suensis sp.nov.)是该属在中国和东亚的首次发现。化石采自甘肃临夏盆地晚中新世柳树组中部。新种以尺寸较小、头型短、枕顶高耸、枕面窄而高、枕嵴无中沟、副枕突短小、下颌上升支距m3较近、前臼齿较小、DP1无后脊、P2原脊孤立、P2和P3后脊细窄而区别于东地中海地区的Diceros neumayri。D.neumayri的分类位置一直是一个争论的焦点,曾在黑犀(Diceros属)和白犀(Ceratotherium属)之间反复变更。研究显示,甘肃黑犀和D.neumayri的一系列共同的原始特征表明它们与更进步的白犀有明显的区别,应该归入黑犀属。

The African black rhino, Diceros bicornis, once widespread across Africa has suffered a massive reduction in both numbers and range during the 20th century, but its origin and phylo- genetic relationship remain debated. Here we report a primitive black rhino from the early Late Miocene of the Linxia Basin in Gansu, China. The new species, Diceros gansuensis, has a brachycephalic skull, a bulbous nasal horn boss followed by a frontal one, anteriorly shortened nasals, a laterally inclined lower border of orbit, a vertical occipital surface, a strongly concave cranial dorsal profile, a very high occiput, and a marked paracone fold.