三棱齿兽科（兽孔目：犬齿兽亚目）的齿系

The dentitions of the Tritheledontidae (therapsida: cynodontia).

作者信息

Gow C E

出版信息

Proc R Soc Lond B Biol Sci. 1980 Jul 17;208(1173):461-81. doi: 10.1098/rspb.1980.0063.

DOI:10.1098/rspb.1980.0063

Abstract

Three previously described monospecific genera of ictidosaurians (Tritheledontidae) are recognized on the basis of their postcanine dentitions. The least specialized is Pachygenelus monus, Watson (1913), the complete dentition of which is described for the first time: five specimens are described and referred to this species. The postcanine teeth of Diarthrognathus broomi, Crompton (1958) are described for the first time; they are derivable from those of Pachygenelus though considerably more specialized. Tritheledon riconoi, Broom (1912), from which the family derives its name, consists of a single specimen containing upper postcanines only; these are not closely comparable with the uppers of the other two genera but bear a strong resemblance to the lower postcanines of Diarthrognathus. The family is closely implicated in the origin of mammals and the possibility of polyphyly in the origin of mammals is raised.

摘要

根据三尖叉齿兽类的犬齿后齿列，识别出了三个先前描述过的单属类群（三尖叉齿兽科）。最不特化的是厚颌兽属的莫氏厚颌兽（Pachygenelus monus），沃森（1913年），其完整齿列首次被描述：描述了五个标本并归入该物种。首次描述了布鲁姆氏双关节颌兽（Diarthrognathus broomi），克伦普顿（1958年）的犬齿后齿；它们虽然比厚颌兽的齿更为特化，但可从厚颌兽的齿演化而来。三尖叉齿兽科得名于里氏三尖叉齿兽（Tritheledon riconoi），布鲁姆（1912年），它仅由一个仅包含上颌犬齿后的标本组成；这些与其他两个属的上颌齿不太可比，但与双关节颌兽的下颌犬齿后齿非常相似。该科与哺乳动物的起源密切相关，并且提出了哺乳动物起源中多系发生的可能性。