论文部分内容阅读
报道并描述了一件来自甘肃临夏盆地的中间乌米兽(Urmiatherium intermedium)头骨化石新材料,该材料产自柳树组上部,属于晚中新世晚期杨家山动物群。中间乌米兽是一种大型的晚中新世牛科动物,角心特化,短且呈薄板状,并且在基部相互靠近。在角心前后方的额骨和顶骨上,发育大片赘生骨疣,这些骨疣与角心一起,合称角器。20世纪初,步林报道了中国北方晚中新世地层中的大量中间乌米兽化石,包括产自山西保德和甘肃庆阳的20多件头骨以及很多破碎的齿列和骨骼。本文报道的乌米兽头骨化石是乌米兽在甘肃临夏盆地的首次发现,将其在中国北方的分布向西扩展到了青藏高原东北缘地带。乌米兽被普遍认为与近旋角羊(Plesiaddax)、和政羊(Hezhengia)和柴达木兽(Tsaidamotherium)等晚中新世“麝牛类”牛科动物具有较近的亲缘关系,但其系统发育地位仍存有争议。相比其他晚中新世“麝牛类”牛科动物,乌米兽的分布较广,从伊朗至中国北方都有分布,但它鲜与其他晚中新世“麝牛类”牛科动物伴生。在临夏盆地,与其伴生的牛科动物目前仅发现中华羚(Sinotragus)一种。
A new skull fossil from Urmiatherium intermedium from Linxia basin in Gansu was reported and described. It originated from the upper part of the Willow Group and belonged to the Yangjiashan fauna in late Late Miocene. The middle Ummy beast is a large Late Miocene bovid, angularly specialized, short and lamellar, and close to each other at the base. In front of the corner of the front and rear frontal and parietal bone, the development of large pieces of neoplastic bone warts, these warts and corner together, together known as the angle. Early in the twentieth century, Julin reported on a large number of intermediate Ulmus fossils from the Late Miocene strata in northern China, including more than 20 skulls and many broken dentitions and bones from Baode, Shanxi and Qingyang, Gansu. The first reported discovery of the um beast skull fossil in this paper in Linxia Basin of Gansu Province extends its distribution in the north of China to the northeast margin of the Qinghai-Tibet Plateau. Ummi beasts are generally considered to have a closer genetic relationship with late Neopluses such as Plesiaddax, Hezhengia and Tsaidamotherium and Musk Beef bovines , But its phylogenetic position remains controversial. Compared with other late Miocene “Musk Beef ” bovids, the distribution of Ummy beasts is broader than that of the other Late Miocene, from Iran to northern China, but it is similar to other Late Miocene "Bovids associated. In the Linxia basin, only bouts of Sinotragus are currently found in bovids associated with it.