安徽潜山古新世裂齿目一新属兼论中国古新世裂齿类

记述了安徽潜山盆地古新世裂齿目一新属种 ,命名为潜水本爱兽 (Benaiusqianshuiensisgen .etsp .nov .)。标本产于望虎墩组下段底部 ,为一带犬齿和完整颊齿列的左下颌骨。新种的主要特点是 :个体较小 ,下齿列齿式 2 + ?·1·4·3,i2略有增大 ,p1存在但退化成单根且侧扁 ,p3无下后尖 ,p4次臼齿化且无下内尖 ,下三角座前后压缩且下前尖退化 ,m3三叶。中国曾经记述的和被认为是裂齿类的古新世哺乳动物共有 9个属种 :Lofochaiusbrachyo dus、Meiostylodonzaoshiensis、Anchilestesimpolitus、Dysnoetodonminuta、Interogaledatangensis、Pletho rodonchienshanensis、Huananiusyoungi、Yuesthonyxtingae和Simplodonqianshanensis。经过仔细比较研究它们的齿列 ,作者认为 ,Lofochaius、Meiostylodon、Interogale、Plethorodon和Simplodon可能属于裂齿类 ,而Anchilestes、Dysnoetodon、Huananius和Yuesthonyx则可能与裂齿类没有很近的亲缘关系。广东南雄盆地上湖组Lofochaiusbrachyodus的P1和P2退化、P4有一定程度的臼齿化、外架窄、主尖锥状、前尖棱和后尖棱的颊侧端内收 ,显示了裂齿类的特点。湖南茶陵盆地枣市组Meiostylodonzaoshiensis的i2增大、上臼齿主尖锥状、柱尖和后附尖发育、前尖棱和后尖棱的颊侧?

A NEW PALEOCENE TILLODONT (TILLODONTIA,MAMMALIA) FROM QIANSHAN,ANHUI,WITH A REVIEW OF PALEOCENE TILLODONTS FROM CHINA

A left lower jaw from the Paleocene Wanghudun Formation of the Qianshan Basin, Anhui Province, southern China is described. It represents a new genus and species of tillodont, named Benaius qianshuiensis gen. et sp. nov. The new species is characterized by the following features: size small, dental formula 2+?·1·4·3, i2 not greatly enlarged, p1 present but reduced and laterally compressed, no metaconid on p3, and p4 submolarized without entoconid. Reexamination of dental features of the Chinese Paleocene tillodonts, including the originally assigned taxa and the reallocated forms of the order, suggests that Lofochaius, Meiostylodon, Interogale, Plethorodon and Simplodon have affinities to the order Tillodontia, whereas Anchilestes, Dysnoetodon, Huananius , and Yuesthonyx do not have close relationships to tillodonts. This conclusion is coincident with the result of the phylogenetic analysis on the basis of the dental characters.