鳥類が飛ぶようになったのは,セロポッドの腕の再編成が先行したからです
James G Napoli1,2,3, Matteo Fabbri4, Alexander A Ruebenstahl5
1Department of Anatomical Sciences, Renaissance School of Medicine, Stony Brook University, Stony Brook, NY, USA. james.napoli@stonybrook.edu.
Nature
|July 9, 2025
まとめ
鳥の飛行に不可欠なピシフォーム骨は 鳥に特有のものではなく 多くのセロポッド恐竜に存在していました 骨の交換は 飛行の進化の重要なステップでした
科学分野:
- 古生物学
- 進化生物学
- バイオメカニクス
背景:
- 鳥のカーパス (手首) は,カーパルの縮小と骨の置換を含む複雑な進化の歴史を持っています.
- 鳥の翼先の安定化と 飛行の自動化に不可欠です
- 以前は,ほとんどのセロポッド恐竜にピシフォームは存在しないと考えられていましたが,それは失われ,後に鳥に再進化したことを示唆しています.
研究 の 目的:
- 恐竜の進化史を調査する
- 骨の遺伝分布を 調べるためだ
- 鳥の飛行の起源における 魚形鳥の役割を理解するために
主な方法:
- モンゴルの2つの新しいセロポッド恐竜標本の前肢骨格の記述.
- 過去に公表された化石の再解釈
- フィロジェネティック分析で,ピシフォームの存在のタイミングを決定する.
主要な成果:
- ピシ型の骨はオビラプトロサウリアとトロオドントイダで特定され,その存在は鳥以外にも知られる.
- ミクロラプター,アンボプテリックス,アンキオルニスを含む様々なセロポッドの種にピシフォームが発見されました.
- ペナラプトラ族の ウルネアに取って代わられ 鳥類の親類の飛行の起源と一致した.
結論:
- 鳥類に特有の新しい骨はなく 恐竜の種にもありました
- 恐竜の飛行器の進化における 決定的な最終段階でした
- この進化の出来事は 鳥だけでなく 熱足恐竜の飛行の起源の近くで起こりました
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