最古老的人类祖先化石大致年龄确定
文章来源:未知 文章作者:enread 发布时间:2011-09-09 05:19 字体: [ ]  进入论坛
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Researchers have confirmed the age of possibly our oldest direct human ancestor at 1.98 million years old. The discovery was made after researchers conducted further dating of the early human fossils, Australopithecus sediba(南方古猿人) , found in South Africa last year.

A series of studies carried out on newly exposed cave sediments1 at the Malapa Cave site in South Africa, where the fossils were found, has assisted researchers to determine their more precise age at 1.98 million years old, making the Malapa site one of the best dated early human sites in the world.

A series of papers published in a special issue of the journal Science provide a new, more precise age for the fossils, as well as more detailed2 studies of the hands, feet, pelvis(骨盆) and brain.

Uranium lead dating of the flowstone, conducted by the University of Melbourne combined with palaeomagnetic(古地磁的) analysis sediments surrounding the fossils, conducted by La Trobe University provide the tightly constrained3 new age.

The team was able to pin down the age of the fossils to within 3000 years of 1.98 million years, a massive advance on the age range of around 200,000 years from the 2010 estimate.

Dr Robyn Pickering of the University of Melbourne's School of Earth Sciences, a lead researcher involved in the dating of the flowstone surrounding the fossils said researchers had long been searching for fossils from this time period to answer questions about the beginnings of our own genus(类,种) Homo.

"Knowing the age of the fossils is critical to placing them in our family tree, and this new age means that Australopithecus sediba is the current best candidate for our most distant human ancestor."

"The results of these studies present arguably the most precise dates ever achieved for any early human fossils," she said.



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1 sediments 8b3acb612b624abdf2c2881bc6928565     
沉淀物( sediment的名词复数 ); 沉积物
参考例句:
  • When deposited, 70-80% of the volume of muddy sediments may be water. 泥质沉积物沉积后,体积的70-80%是水。
  • Oligocene erosion had truncated the sediments draped over the dome. 覆盖于穹丘上的沉积岩为渐新世侵蚀所截削。
2 detailed xuNzms     
adj.详细的,详尽的,极注意细节的,完全的
参考例句:
  • He had made a detailed study of the terrain.他对地形作了缜密的研究。
  • A detailed list of our publications is available on request.我们的出版物有一份详细的目录备索。
3 constrained YvbzqU     
adj.束缚的,节制的
参考例句:
  • The evidence was so compelling that he felt constrained to accept it. 证据是那样的令人折服,他觉得不得不接受。
  • I feel constrained to write and ask for your forgiveness. 我不得不写信请你原谅。
TAG标签: fossils human age
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