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A new species of Gobiconodon (Triconodonta, Mammalia) and its implication for the age of Jehol Biota
LIChuankui WANGYuanqing HUYaoming MENGJin 《科学通报(英文版)》2003,48(11):1129-1134
A new species of Gobiconodon is found from the Yixian Formation of western Liaonlng, China. The new taxa,G zofiae sp. nov., has a confluent opening for branches Ⅱand Ⅲ of the trigeminal nerve on the anterior lamina of the petrosal. G zofiae sp. nov. is similar to Repenomamus in having an ossified Meckel‘s cartilage connecting the lower jaws and ear region. The new species, with enlarged I^1/I1, posteriorly located infraorbital foramen and four mental foramina,distinctly differs from the other species of Gobiconodon. The new material indicates that Gobiconodon has four, not five,upper molariforms. The presence of Gobiconodon in Jchol Biota makes it possible to correlate Jehol Biota with faunas in eastern Asia and North America, and suggests the age of the Yixian Formation to be Early Cretaceous. 相似文献
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长期以来,科学家认为人类起源于非洲,并在那里生活了最初几百万年。但是在某个时候,我们的祖先开始走出他们的故乡,标志着全球扩散的开始。然而,确定他们为何与何时离开非洲这已经证明是件困难的事情,因为早期人类化石稀少。不过如今来自格鲁吉亚共和国的两块古代头盖骨提供了第一批走出非洲的人类的最有力证据。根据5月12日《科学(science)》的一 相似文献
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The brain morphology of Homo Liujiang cranium fossil by three-dimensional computed tomography 总被引:2,自引:0,他引:2
The Liujiang cranium is the most complete and well-preserved late Pleistocene human fossils ever unearthed in south China. Because the endocranial cavity is filled with hard stone matrix, earlier studies focused only on the exterior morphology of the specimen using the traditional methods. In order to derive more information for the phyletic evaluation of the Liujiang cranium, high-resolution industrial computed tomography (CT) was used to scan the fossil, and the three-dimensional (3D) brain image was reconstructed. Compared with the endocasts of the hominin fossils (Hexian, Zhoukoudian, KNM-WT 15000, Sm 3, Kabwe, Brunn 3, Predmost) and modern Chinese, most morphological features of the Liujiang brain are in common with modern humans, including a round brain shape, bulged and wide frontal lobes, an enlarged brain height, a full orbital margin and long parietal lobes. A few differences exist between Liujiang and the modern Chinese in our sample, including a strong posterior projection of the occipital lobes, and a reduced cerebellar lobe. The measurement of the virtual endocast shows that the endocranial capacity of Liujiang is 1567 cc, which is in the range of Late Homo sapiens and much beyond the mean of modern humans. The brain morphology of Liujiang is assigned to Late Homo sapiens. 相似文献
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甘肃泾川人类头盖骨化石发现于1976年, 1984年进行了简要报道. 但缺少遗址的同位素年代, 对头骨形态及演化特点的观察研究也很初步. 为进一步发掘泾川头骨蕴含的科学信息, 2006年对人化石发现地点进行了地层考察、年代测定, 并开展对人化石的进一步研究. 本项研究采用光释光法对泾川人化石出土地点进行了年代测定, 分别获得15, 48, 7.9 ka的结果. 综合地层考察、伴生动物化石、石制品研究, 测年结果中15~48 ka可能更加接近泾川人化石的真实年代. 人化石研究显示, 所比较的头骨大多性状在更新世晚期人类与现代人间无明显差异, 所以泾川头骨与现代人接近的形态特征并不与其较早的年代相矛盾. 同时, 对更新世晚期人类头骨测量数据的主成分分析显示泾川头骨分布位置偏离现代人主要分布区域, 除说明更新世晚期人类头骨测量性状变异范围较大外, 可能提示泾川头骨有一定的原始性. 相似文献
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2005年,周口店北京猿人化石寻找工作委员会成立,同时在全国范围内展开了对丢失的北京人化石的再一次寻找。中央电视台《走近科学》栏目组跟踪拍摄近三年,制作出了大型系列节目《再找“北京人”》。笔者作为这一系列片的导演,亲历了寻找活动全过程。在关于头盖骨化石下落的众多线索当中,天津的美军兵营曾经是一个最大的谜团。 相似文献