THE ARAGONIAN VERTEBRATE FAUNA OF XIACAOWAN, JIANGSU——7. APLODONTIDAE (RODENTIA, MAMMALIA)

<正> The fossils which form the subject of the present study were collected in the recent years from the middle Miocene Xiacaowan Formation at three sites, Songlinzhuang, Shuanggou and Zhengji of Sihong, Jiangsu. Most of the material from the first two sites have been reported previously as Prosciurus sp. (Li et al., 1983). Further study indicates that all the specimens mentioned and the M_1/2 previously assigned to Prosciurus? shantungensis Rensberger et Li (1986) are quite different from those of Prosciurus, but represent a new genus, Ansomys. In some features, the new form resembles Plesispermorphilus? descedens of Europe. For the two taxa a new subfamily Ansomyinae is created. It is morphologically intermediate between Meniscomyinae and Allomyinae, and may be the sister taxon of the higher aplodontids Allomyinae and Aplodontinae.