ON ALLOPTOX (LAGOMORPHA, OCHOTONIDAE)FROM THE MIDDLE MIOCENE OF TONGXIN, NINGXIA HUI AUTONOMOUS REGION, CHINA

<正> Rather abundant sample of Alloptox, including skulls, maxillae, mandibles and isolated teeth, was collected from the middle Miocene of Tongxin County, Ningxia Hui Autonomous Region during the two field seasons in 1985 and 1986, when reconnaissance and geological mapping of the middle Miocene in this region were conducted by a joint party of the Institute of Vertebrate Paleontology and Paleoanthropology, Academia Sinica (IVPP) and the Bureau of Geology, Ningxia Hui Autonomous Region. The specimens came from 18 localities pertaining to 9 levels in a sequence of middle Miocene fluviatile sediments with a thickness of ca. 200m. Except for the specimens assigned to Alloptox sp. from locality Taoziliang, all are recognized as Alloptox gobiensis. The present paper deals with only their dental morphology which is probably phylogenetically significant. Altogether 327 specimens of Alloptox gobiensis and 27 specimens of Alloptox sp. have been described. The text figures are drawn by the authors and Mrs. Yang Mingwan. All teeth are presented as left ones, the abbreviatd word "inv" is used under the figures of right teeth. All specimens are stored in IVPP under the inventory number V8822-V8839. The authors are much obliged to Prof. Qiu Zhanxiang for reading and correcting the English version of this paper.     

Alloptox gobiensis(兔形目 ,鼠兔科 )头骨形态及系统位置

产于宁夏同心地区中中新世红柳沟组的戈壁跳兔 (Alloptoxgobiensis)头骨化石 ,是Al loptox属头骨化石的首次发现。其主要特征是 :个体较大。颅顶平缓 ,额骨有眶上嵴且两侧平行。颞嵴、上枕骨、项嵴和枕外嵴发育。眶裂后的翼蝶骨上排列有 6个孔。有外颈动脉孔 ,颈静脉孔为圆形小孔。下颌骨水平支唇侧上缘前倾 ,垂直支前缘有一深沟 ,冠状突位于垂直支前缘唇侧壁中部 ,呈薄片状。基于头骨性状的支序分析结果表明 ,Alloptox与非洲的Kenyalagomys亲缘关系最近 ,应归入亚科Sinolagomyinae。Alloptox和Kenyalagomys可能起源于亚洲的共同祖先 ,由Sinolagomys或与其相近的属种演化而来 ,在新近纪早期迁入非洲。