重庆巫山更新世反刍类臼齿的新类型及伴生的鹿化石(英文)

An extraordinary pattern of ruminant molars and associated cervids from the Pleistocene of Wushan,Central China

新月形颊齿是反刍类的鉴定特征之一,而反刍类的上臼齿通常由4个新月形主尖组成。2008年在重庆市巫山县庙宇镇新城村堰头溪地点的一建筑项目中从黏土质地基中挖掘出一件带有上颊齿的反刍类上颌骨残段,标本上的上臼齿由5个新月形主尖组成。伴生的其他动物有更新世麂属未定种(Muntiacus sp.)和黑鹿(Cervus(Rusa) unicolor)。形态学研究显示堰头溪标本的上臼齿代表一种新的新月形上臼齿类型,它不同于见于部分胼足类(tylopods)的5尖型上臼齿,例如古近纪的石炭兽类和xiphodontids以及分布于渐新世和中新世的真兽类。堰头溪标本上臼齿中的第五个主尖被诠释为原尖基部舌侧的齿带过度发育而成,与胼足类的舌侧主尖非同源关系。堰头溪标本代表一个新的种类,其分类位置暂定为麂亚科的麂属,即黄氏麂Muntiacus?huangi sp.nov.。

Selenodont cheek teeth are diagnostic characteristics of ruminants, in which the upper molars are usually composed of four selenodont main cusps. During a local housing construction at Yantouxi near the Longgupo Site at Miaoyu Town of Wushan County in Chongqing Municipality of Central China, a mandibular fragment with extraordinary molars composed of five main selenodont cusps was uncovered with association of the Pleistocene Muntiacussp. and Cervus （Rusa） unicolor. The morphological study shows that it is a new pattern of selenodont molars different from five-cusped upper molars of some tylopods such as anthracotheres and xiphodontids from the Paleogene as well as cainotheriids from the Oligocene to Miocene. The fifth selenodont cusp is interpreted as an overdevelopment of cingulum around the anterior lingual base of the protocone. The taxonomic status of the animal is placed temporarily in Muntiacinae as Muntiacus ？ huangi sp. nov.