中国穿山甲和马来穿山甲头骨量度的测定及比较

全球共有7种穿山甲。本文报道的是中国穿山甲和马来穿山甲的头骨形态学资料,涉及头骨特征描述和一些形态学指标测定。被测定的指标主要有颅全长、基底长、腭长、眶间宽、后头宽、鼻骨长、鼻骨宽、脑颅高、听泡长和下颌长,并且在这两个物种之间进行了比较。结果表明,(1)这两个物种头骨形态十分相似,但马来穿山甲头骨细长,听泡长小于10mm(n=12),鼻骨狭长,前后部宽窄相似,两鼻骨外侧缘内凹或平行,鼻骨宽长之比值小于0 3000(0 2025～0 2811,n=12);而中国穿山甲头骨较粗短,听泡长大于11mm(n=46),鼻骨宽短,后部较前端宽,外侧缘外凸,鼻骨宽长之比值大于0 3000(0 3154～0 5325,n=33)。这些异同之处,可以作为区分这两个物种的依据。(2)中国穿山甲华南亚种与海南亚种头骨各变量之间的差异不显著(P>0 05),用颅全长是否大于83mm来区分这两个亚种不能成立,但海南亚种头骨上颌骨的颧突和鳞骨的颧突通常越过眶颞窝完全相接触,如果不是这样,则在它们之间有一个小的骨质棒状结构将它们连接起来。

Measurement and Comparison of Skull Variables in Chinese Pangolin and Malayan Pangolin

There are 7 species of pangolin in the world. The data of skull morphology on Manis pentadactyla and Manis javanica were reported in this paper, which involved the measurement and comparison of skull variables of the 2 species. Measured variable include the greatest length of skull, the basilar length, the palatilar length, the greatest cranial breadth, the inter orbital breadth, the length of auditory bulla, the height of brain case, the nasal bone length, the greatest breadth of nasal bone, and the mandibula length. All variables measured were compared respectively between the 2 species. The results indicated that: (1) Skulls of the 2 species were very similar in shape, an elongated cone, but Manis javanica was thinner and longer, the length of auditory bulla was no more than 10 mm (n=12); nasal bone was narrower and longer, nearly the same width throughout or a slight concave at the middle both sides; the width length ratio was less than 0.300 0 (0.202 5-0.281 1, n=12).Compared with skull of Manis javanica, Manis pentadactyla was thicker and shorter; the length of auditory bulla was longer than 11 mm (n=46); nasal bone was wider and shorter; and wider at the posterior than at front part; both sides was convex; the width length ratio was more than 0.300 0 (0.315 4-0.532 5, n=33).The differences between 2 species might be regarded as basis of identifying them. (2) The skull difference between Manis pentadactyla aurita and M. p. pusilla was not significant (P>0.05), so it is untenable to identify the 2 subspecies on the basis of whether their skull length is longer than 83 mm or not. But, at all events, the maxillary bone and the squamosal process of skull of M. p. pusilla are usually completely bridged the orbito-temporsal fossa, their tips touching, or, if they don't quite touch, a small bony element between them completes the bridge.