鳥系アーコサウルスの体形と運動運動生物力学の進化をリンクする
Vivian Allen1, Karl T Bates, Zhiheng Li
1Institut für Spezielle Zoologie und Evolutionsbiologie, Friedrich-Schiller-University Jena, 07743 Jena, Germany.
Nature
|April 26, 2013
まとめ
鳥の運動の進化は,テロポッド恐竜の後肢の姿勢の漸進的な変化を伴い,マニラプトラの加速した変化が飛行に関連していた. 尻尾の縮小ではなく前肢の拡大が,この進化に大きく影響した.
科学分野:
- パレオントロジー・パレオントロジー
- バイオメカニクス バイオメカニクス
- 進化生物学の進化生物学について
背景:
- 生きている鳥 (ネオルニテス) は,羽毛による飛行と,ひっくり返った後肢による独特の運動能力を発揮しています.
- これらの特徴の進化的起源は議論されている.
- コンピュータモデリングと例外的な化石発見により,定量的な生体力学的分析が可能になります.
研究 の 目的:
- アーコサウリア全域における運動生物力学の進化的傾向を定量化するために.
- 鳥の系統における後肢の姿勢と質量中心の進化を調査する.
- 鳥類の運動運動の進化に影響を与える重要な形態学的要因を特定する.
主な方法:
- 17種のアーコサウルスの骨格の大きさから3Dデジタル再構築を活用した.
- 特別に保存されている羽毛類 (Microraptor, Archaeopteryx, Pengornis, Yixianornis) も含まれている.
- 定量化された全身の比率と重心位置.
主要な成果:
- 後肢の姿勢は,熱足類にわたって徐々に進化し,マニラプトラに加速した.
- 尻尾の縮小ではなく,胸肢の拡大が,重心部と後肢の姿勢に強く影響した.
- マニラプトラの加速した形態機能的傾向は,飛行の進化と相関する.
結論:
- 鳥の飛行の進化は,胸部と骨盤の両方の四肢の解剖学的変化と関連しています.
- この研究は,後肢の姿勢の進化の主な原動力として,尾の縮小に関する伝統的な見解に異議を唱える.
- 鳥の運動の起源における前肢と後肢の適応の複雑な相互作用を示唆している.
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