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

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.