排序方式: 共有72条查询结果,搜索用时 31 毫秒
51.
52.
距今1700万年前至1000万年前,巨型动物群生活在澳大利亚,大约5万年前或6万年前,人类登上澳大利亚大陆之后不久,所有这些动物都神秘地消失了.这些动物活着的时候是什么样子呢?考古学家根据动物化石,向我们展示了它们的不凡风姿. 相似文献
53.
54.
中国科学院古脊椎动物与古人类研究所朱敏研究员领导的早期脊椎动物课题组报道了迄今最古老基干四足动物——奇异东生鱼(Tungseniaparadoxa).该属名为纪念中国泥盆纪脊椎动物的早期研究者、已故地质学家刘东生而定。东生鱼化石发现于云南昭通早泥盆世地层,距今约4.09亿年,它将四足动物支系的演化历史前推了1000万年。研究人员利用高精度X射线断层扫描和计算机三维虚拟重建技术复原了东生鱼的颅腔及相关神经、 相似文献
55.
56.
57.
58.
Fan Jin FuCheng Zhang ZhiHeng Li JiangYong Zhang Chun Li ZhongHe Zhou 《科学通报(英文版)》2008,53(18):2820-2827
Protopteryx, a monotypic fossil bird discovered from the Sichakou basin in Fengning, Hebei, is the most primitive enantiornithine currently known. The bird-bearing strata do not contain the index fossils of the Yixian Formation in western Liaoning; the fish and bird fossils have more primitive features than the related forms found in the Yixian Formation, and the conchostracans are those usually distributed in the Dabeigou and Dadianzi formations in northern Hebei. Besides, the Protopteryx-bearing strata underlie the deposits bearing the index fossils of the Yixian Formation in the neighboring basin. Thus, it could be confirmed that the horizon of Protopteryx should be lower than the Yixian Formation, and Is approximately equivalent to the Dadianzi Formation in northern Hebei. This is the lowest horizon of the known fossil birds in China and Mesozoic enantiornithine birds in the world. Accompanying Protopteryx, there are other birds, acipenseriform fishes, salamanders, and mammals, which compose the Peipiaosteus fengningensis-Protopteryx fengningensis assemblage. This new assemblage traces the vertebrate evolution history of the Jehol Biota back to 130.7 Ma before. It is suggested that the demarcation of the Jehol Biota should be based on the large-scale tectonic-sedimentary cycles, and Peipiaosteus, instead of Lycoptera, could be taken as the vertebrate representative of the Jehol Biota. 相似文献
59.
黄万波 《重庆三峡学院学报》2008,24(4)
本文通过对长江流域人类化石的分折认为,从200万年前的"巫山匠人"至5 000年前的"巴人",其体质特征是一脉相承的,其间既没有"断档",也未见外来文化的渗透.有鉴于此,笔者同意刘东生院士的意见,即把长江流域的人类化石统称为"东亚型"人.他们生活在青藏高原东部的森林、河流环境中.再者,依据长江流域出土的石制工具和与人类化石伴生的近200种动物化石反映的本土信息表明,"东亚型"人的起源于长江流域大三峡,且连续繁衍至今. 相似文献
60.
科学家在中国长江流域发现了世界上最古老的灵长类动物化石,距今5500万年。这种被命名为"阿喀琉斯基猴"的灵长类动物体型很小,还不及侏儒鼠狐猴。侏儒鼠狐猴是当前世界上最小的灵长类动物。在《自然》杂志上,科学家对这种最古老灵长类动物的骨架进行了描述。体重不到1盎司 相似文献