エチオピアから発見された新しいヒト類の足は,複数のプレオセンの二足の適応を示している
Yohannes Haile-Selassie1, Beverly Z Saylor, Alan Deino
1The Cleveland Museum of Natural History, Cleveland, Ohio 44106, USA. yhailese@cmnh.org
Nature
|March 31, 2012
まとめ
東アフリカから発見された新しいヒト類の足の化石は,以前は知られていなかった,反対の大きい足の指を持つ種を明らかにしており,これはプレオセンの末期における多様な人間の祖先の動きを示している.
科学分野:
- 古人類学は,古人類学である.
- 人間の進化 人類の進化
- パレオントロジー・パレオントロジー
背景:
- 東アフリカにおける初期のプレオセンの末期 (約340万年前) は,ヒト類の進化を理解する上で極めて重要です.
- 現存する化石記録は,特定の運動能力の適応を備えた,支配的なホミニン種,アウストラロピテクス・アファレンシス (Australopithecus afarensis) が存在していたことを示唆している.
研究 の 目的:
- 東アフリカから新たに発見されたホミニン・ペダルの要素を分析するために.
- これらの化石が,既知のホミニン種に関連して与える分類学的および運動学的影響を決定する.
主な方法:
- 新しく発見されたホミニンの足骨の形態学的分析.
- Ardipithecus ramidusとAustralopithecus afarensisを含む化石ホミニンとの比較分析について.
- 化石元素の放射線年代測定. 化石元素の放射線年代測定. 化石元素の放射線年代測定. 化石元素の放射線年代測定.
主要な成果:
- 発見されたペダルの要素は,Australopithecus afarensisと異なるホミニン種に属しています.
- この新しい種は,前向きな親指を示しており,これは以前はArdipithecus ramidusのような以前のホミニンと関連付けられていた特徴です.
- 化石は,アルディピテクス・ラミドゥス (Ardipithecus ramidus) のような運動器の適応が,プレオセンの末期まで続いたことを示している.
結論:
- 異なる運動戦略を持つ複数のホミニン種が,プレオセンの初期に東アフリカで共存していた.
- この発見は,この期間のヒト類の多様性と適応に関する以前の仮定に異議を唱えている.
- この発見は,ヒト類の進化のモザイクの性質と,後のヒト類の種で原始的な特徴の保持を強調しています.
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