作者:西冈佑一郎,甲能直树,工藤雄一郎
摘要:对产自中国川渝地区的“Proboselaphus watasei Matsumoto, 1915”的分类学修订表明,这一属种名称是无效的。其正型标本为属于同一个体的颅骨及下颌骨,现收藏于日本千叶县国立历史民俗博物馆,由直良信夫重新发现。基于有角类的一些一般特征,如细小的骨质角芯和高冠的颊齿,“Proboselaphus watasei”在建立时被认为与南亚地区现生蓝牛(Boselaphus tragocamelus)亲缘关系密切。然而,对正型标本的重新观察表明,其颅骨及牙齿的形态具有鹿科的典型特征,如额顶面向背侧弯曲,基枕骨轮廓呈三角形,以及臼齿具有相互分离的前叶和后叶。正型标本的臼齿形态与水鹿(Cervus unicolor)具有相似性,二者均具有显著的附属结构(刺、齿带以及附尖), 并且与中国南方地区更新世地层中的Cervus cf. C. unicolor大小相仿。这一修订表明,更新世期间没有任何蓝牛冠群成员扩散至东亚地区。
关键词:中国,第四纪,哺乳动物,牛科,鹿科
Taxonomic revision of the holotype of Proboselaphus watasei Matsumoto, 1915 (Bovidae, Artiodactyla) from Chuanyu area, China
NISHIOKA Yuichiro,KOHNO Naoki,KUDO Yuichiro
Abstract A taxonomic revision of Proboselaphus watasei Matsumoto, 1915 (Bovidae, Artiodactyla) from the Pleistocene of Chuanyu area, China demonstrates that this genus and species names are invalid. The holotype with a skull and mandibles was recently rediscovered in the fossil collection by Nobuo Naora, which is housed in the National Museum of Japanese History, Chiba Prefecture, Japan. Proboselaphus watasei was described as a closely-related species to living nilgai, or Boselaphus tragocamelus, in South Asia, based on general characteristics of pecorans, such as small bony horn-cores and hypsodont cheek teeth. However, the cranial and dental morphologies re-examined in the present study clearly show that the holotype has cervid-specific characteristics: e.g., the fronto-parietal surface curving dorsally, the basioccipital with a triangular outline, and molars with isolated anterior and posterior lobes. The molars of the holotype are comparable to those of Cervus unicolor, in having strong accessary structures (or spurs, cingulums/cingulids, and styles/stylids), and are as large as those of Cervus cf. C. unicolor from the Pleistocene deposits in southern China. This taxonomic change suggests that any crown-boselaphins had not dispersed into East Asia since the Pleistocene.
Key words China, Quaternary, mammal, Bovidae, Cervidae