本文描述了产自河南渑池河堤组任村段上部化石层中的鬣猫类新材料, 并创建了渑池东方翼齿兽(新种) Orienspterodon mianchiensis sp. nov.。其与属型种O. dahkoensis主要区别在于: p4三个主尖排列于一条线上, 下跟座中下次尖明显; 下臼齿均存在更为清晰的下后尖, 下原尖与下前尖舌侧侧扁, 下三角座从m1—m3依次增大; m1—m2中下跟座更为发育、开阔, m3下跟座较为退化。基于标准贝叶斯的系统发育研究, “全兼容”树中显示O. mianchiensis与O. dahkoensis为姐妹群, Orienspterodon归属于鬣猫亚科(Hyainailourinae)中。根据下裂齿平均长度的回归分析, 重建Orienspterodon的体重约为155—174 kg。根据牙齿测量数据,并结合牙齿表面釉质结构的显微特征, 推断O. mianchiensis的饮食中肉类成分占据绝对优势, 其并不具备大量食骨的能力。

A new hyainailourid (Hyaenodonta, Mammalia), Orienspterodon mianchiensis sp. nov., is reported from the Rencun Member of the Heti Formation in Mianchi County, Henan. The new taxon differs from the type species Orienspterodon dahkoensis by the following characters: three main cusps on p4 arranged in a straight line, a distinct hypoconid on p4 talonid; presence of a distinct metaconid on all molars, lingually compressed paraconid and protoconid on m2–3, increasing length of trigonid from m1–3; more developed talonid on m1–2, and more reduced talonid on m3. Our standard Bayesian “allcompat” phylogenetic analysis suggests that O. mianchiensis and O. dahkoensis are sister groups, occupying a basal position within Hyainailourinae. We also conduct a regression analysis based on the mean length of three molars, estimating the body mass of Orienspterodon in the range of 155–174 kg. Several dental indices and tooth enamel microstructures indicate that the diet of Orienspterodon mianchiensis is primarily meat-based, and this hyainailourid lacks the capability of a bone-cracking predator. The reconstruction of body mass and the analysis of diet contribute to our understanding of the ecological dynamics and evolutionary adaptations of Orienspterodon. These data provide a foundation for future research on the paleoecology of the hyainailourids.

国家自然科学基金(42072023)资助