作者：黄学诗

摘要：A new Pentalophodon (P. qingyangensis sp. nov.) represented by a rather complete mandible with M₃ (V. 5027 type) and a femur fragment discovered by the commune members in Qingyang district, Gansu, is described. It occurs together with ?Machairodus sp. and Gazclla cf. blacki.  The fossils are probably of Lower Pliocene age.
    Diagnosis: mandible relatively longer, lower third molar with six fully developed transverse ridges and a hind talonid, pretrites and post-trites all alternating in arrangement and slightly oblique to the long axis of the tooth, each pretrite composed of a single conical cone, the post-trite consists of two conules, ridges close to each other, relatively low crown, enamel surface rather smooth, cement not abundant.
    P. qingyangensis differs from P. simplex in having pretrite composed of single conical cone in all ridges which are closely arranged one with other and with little cement. P. qingyangensis is more similar to P. yüsheensis in the structure of the lower third molar, but the latter has larger size, higher crown and more developed cingulum, pretrites and post-trites are more strongly oblique to the long axis of tooth than in the former. P. qingyangensis differs distinctly also from the Indian species. The third molar differs from that of P. falconeri in having smooth surface of enamel and in lacking central cones, and from that of P. sivalensis in that the valleys between the ridges are wider, cones split strongly from anterior to posterior and enamel having much small tubercles.
    P. qingyangensis is probably more primitive than the above four species.

卷期：13卷 04期

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