The finds, revealed in Nature magazine, mainly consist of teeth and jaw fragments, but also include parts of feet and hands. Scientists say the features of a foot bone uncovered at As Duma, in the north of the country, prove that the hominid it belonged to walked upright like present-day humans. All the finds belong to the Ardipithecus ramidus species, which was first discovered a decade ago.

　　Sileshi Semaw, of the Craft Stone Age Institute, described the find as "very important" because it confirmed that hominids walked upright on two feet up to 4.5 million years ago. The age of the remains was determined by dating nearby volcanic material.

　　Hominid意为“原始人类，人科中的灵长类”，其形容词形式表示“人种的，人科的，灵长类的”。
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据悉，这些原始人类的化石碎片在出土前与犀牛、长颈鹿、猴子、河马，以及羚羊的遗体埋藏在一起，据检测，这些化石大约有430-450万年的历史。研究小组表示，这些化石都属于拉密达猿人种类。科学家推测，它可能是最早的原始人类，是人类最早的远祖。

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