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哺乳动物的颊齿分前臼齿和臼齿.两组牙齿形态有差别,但各组内牙齿形态一般由前向后渐变.本文报道新发现的一中生代对齿兽类哺乳动物,其前臼齿与臼齿在形态与功能上有过渡,但臼齿本身从前向后分3个区段,形态不连续.这一齿列特征在现生哺乳动物和其它化石类群中从无记录.这一现象
The cheek teeth of mammals were divided into premolar teeth and molar teeth.The tooth morphology of the two groups differed, but the morphology of the teeth in each group changed gradually from anterior to posterior.This paper reports a newly discovered Mesozoic mammalian tooth, mammalian premolar and molars There is a transition in morphology and function, but the molar itself is divided into three sections from the former back, the shape is not continuous .This dentition features in the existing mammals and other fossil groups from no record .This phenomenon