Study for Miocene Hominoids and Their Palaeoenvironment in East Africa

我们对原始人起源的了解非常有限，而这是现代人类学中一个有趣而重要的课题。本研究项目是在非洲中新世古人类进化研究和古环境分析的基础上进行的，因为东非中新世晚期古人类起源的可能性非常高。在肯尼亚北部和扎伊尔东部进行了古人类学、地质学和古生物学调查。在野外季节发现了许多化石标本。该分类群扩展到中新世中晚期的哺乳动物、爬行动物、鱼类、软体动物和树木，包括一个大型人猿，肯尼亚猿、尼扬猿和维多利亚猿。在肯尼亚北部Samburu Hills的Namurungule组（9Ma）中发现了一种大型类人猿Samburu hominoid，该组的生存环境与北非和欧洲相似，被认为是林地或稀树草原。在肯尼亚北部Nachola地区的Aka-Aitheputh组（15Ma）中也发现了大量中型类人猿Kenyapithecus。动物和植物的组合表明，这种人科动物可能生活在森林环境中。臼齿牙釉质分析表明，这两种古人类的食物都可能是坚硬的东西。在肯尼亚猿人中发现了高度的两性二型性，而在桑布鲁人猿中则不清楚。肯尼亚猿人的基本运动模式可能是具有垂直攀爬活动的四足行走。由于具有陆地杂食习性的可能性，大型身体和布齿兽臼齿的结合可能表明桑布鲁类人猿存在早期两足行走的可能性。这些证据并不支持Simons和Pilbeam提出的最早的肯尼亚猿人理论。桑布鲁人科动物的系统发育状况尚不清楚，但有可能是最早的人科动物。继续在桑布鲁山和东非的其他遗址进行挖掘是非常必要的。少

Our knowledge of hominid origin is very limited while it is an interesting and importnat subject in modern anthropology. This research project has approached it on the basis of the evolutionalry study of African Miocene Hominoids and analysis of the palaeoenvironment, because of a very high possibility of the hominid origin in East Africa of late Miocene. In northern Kenya and eastern Zaire, palaeoanthropological, geological and palaeontological surveys have been conducted.Many fossil specimens were discovered through the field seasons. The taxa extend to Mammals, reptiles, fishes, molluscas and trees of the middle-late Miocene including a large hominoid, Kenyapithecus, Nyanzapithecus and Victoria-pithecus.A large hominoid, Samburu hominoid, was discovered from the Namurungule Formation (9Ma) in Samburu Hills, northern Kenya, of which environment is supposed to be a woodland or savanna because of a coexistence of bovids and equids which are similar to those of northern Africa and Europ … More e. A great number of specimens of middle-sized hominoids, Kenyapithecus were also discovered from Aka-Aitheputh Formation (15Ma) in Nachola area in northern Kenya. The faunal and floral assembleges show that this hominoid might have lived in a forest environment.Molar enamel analysis tells the food of both hominoids might have been hard stuffs. A highly sexual dimorphism was seen in Kenyapithecus while it is not clear in Samburu hominoid. A basic locomotor pattern of Kenyapithecus might be quadrupedalism with a vertical climbing activity. A combination of large-sized body and bunodont molar may suggest some possibility of an incipient bipedalism in Samburu hominoid, because of a possibility of terrestrial omnivorous habit.The evidences do not support the earliest hominid theory of Kenyapithecus by Simons and Pilbeam. The phylogenic status of the Samburu hominoid is not clear but there is some possibility as an earliest member of hominids. It is very necessary to continue excavations in the Samburu Hills and other sites in East Africa. Less