分类: 地球科学 >> 地质学 提交时间: 2018-04-04 合作期刊: 《古脊椎动物学报》
摘要: A new specimen of kubanochoeres has been discovered from the Maida locality, Linxia Basin, Gansu Province, China, and a new species, Kubanochoerus parvus sp. nov., has been created based on the unique partially broken cranium. The new species has a relatively small body size similar to K. massai and K. minheensis. The new species, which possesses relatively wide cheek teeth that resemble those of K. massai and many derived characters that are similar to K. gigas, may represent a separate lineage of the Eurasian kubanochoeres. The horizon of the Maida locality is speculated to be the upper Hujialiang Formation or lower Liushu Formation, and the new species is possibly the youngest known kubanochoere. Based on the comparison of the known kubanochoere, Libycochoerus is suggested to be a synonym of Kubanochoerus, while K. robustus and K. lantienensis are synonyms of K. gigas. There is not sufficient evidence to support the subdivision of K. gigas at the subspecies level. Kubanochoerus gigas is speculated to have derived from more primitive forms that existed earlier than K. massai, and the new species may be derived from K. massai or other earlier forms. Kubanochoerus minheensis, which bears a relatively small body size and rudimentary sub-lophodont dentition, is suggested to be another separate lineage of the Eurasian kubanochoeres.
分类: 地球科学 >> 地质学 提交时间: 2018-04-04 合作期刊: 《古脊椎动物学报》
摘要: Recent fieldwork at Pleistocene cave sites in the Chongzuo area in Guangxi Zhuang Autonomous Region has yielded 33 isolated teeth of fossil hylobatids. Comparisons indicate that the teeth can all be referred to a single species of Nomascus, but the material is insufficient to assign it to a particular species. The molars are slightly larger on average than those of extant species of Nomascus, but unlike contemporary great apes from the Pleistocene of southern China, the hylobatids do not seem to have undergone a change in dental size through time. Nomascus is not present in the Chongzuo area today, but historical records indicate that the genus may have been widely distributed across southern China in the recent past.
分类: 地球科学 >> 地质学 提交时间: 2018-02-26 合作期刊: 《古脊椎动物学报》
摘要: Reinvestigation of the Early Cretaceous eutherian mammal Endotherium niinomii Shikama, 1947, based on the impressions of the type specimen, casts made from the impressions, and the original description, indicates that E. niinomii is characterized by the following characters: decrease in size from the m1 to the m3; a moderate height difference between the trigonid and talonid of lower molars; blunt lower molar cusps; the protoconid being the largest among the trigonid cusps; the paraconid being as tall as the metaconid; the p3 not being obviously reduced; and possible possession of five lower premolars. These characteristics clearly distinguish E. niinomii from other known Cretaceous eutherians, and support its taxonomic identity as a valid taxon.