记三列齿科一新属

<正> 本文所记述的标本,是1972年袁祖银同志与笔者在云南进行野外工作时采集的。化石产于云南禄丰的下禄丰组深红层地层中,与周明镇教授描述过的禄丰兽(Lufengia)同层。由于风化,头骨缝合线不清楚,但就头骨显示出的其他特征,不难看出,此标本系代表三列齿科(Tritylodontidae)中一新种属。本文承王哲夫、侯晋封同志分别照相和绘图,谨此表示感谢。

A NEW GENUS OF TRITYLODONTOIDEA

A skull of Tritylodontoid was collected from Lufeng, Yunnan Province by Yuan Zuyin and the author in 1972. The specimen was found at Zhang-jiawan, in Lower Lufeng Formation from which Lufengia had been discovered (Chow and Hu, 1959). The present skull here described was weathered and damaged. It is 74.6mm. in length andi with a diastema 15.2mm. long. There are seven cheek teeth on each side. In view of the structures of the skull, it is doubtless a member of Tritylodontoid and by its special characters, the present author considers it as a new form of the group and names it as Dianzhongia longirostrata gen. et sp. nov.The diagnosis of Dianzhongia is as follows:Only a couple incisors. Jugal comparatively strong and not extending outwards judging by its remaining basal part. Diastema long. Upper cheek teeth with two outer, three median, and two inner cusps.The geological age of the Dianzhongia-bearing deposits is probably of Lias Stage.