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テロポッド恐竜の尾を駆動する水中運動
Nizar Ibrahim1, Simone Maganuco2,3, Cristiano Dal Sasso3
1Department of Biology, University of Detroit Mercy, Detroit, MI, USA. ibrahini@udmercy.edu.
Nature
|May 8, 2020
まとめ
スピノサウルス・エジプティアカスという 巨大なセロポッドは 独特の羽根のような尾を持ち 水中での推進力に 強い証拠を 提供していました この発見は 恐竜の生息地に関する以前の仮定に 異議を唱え 古代の爬虫類が水中の環境に 大きく侵入したことを示唆しています
科学分野:
- 古生物学
- 脊椎動物学
- バイオメカニクス
背景:
- 非鳥類の恐竜は 歴史的に地上の動物と考えられていた.
- これまでの半水生恐竜の理論は,特にスピノサウリドは,論争の的でした.
- スピノサウルス・エジプティアカスは 大型の白亜紀のセロポッドで 魚を食べた可能性のある水生的な生活様式を示唆する様々な適応を示しています
研究 の 目的:
- Spinosaurus aegyptiacusの水中推進構造の 明確な証拠を提供するために
- スピノサウルスの 独特の尾の形状の バイオメカニズムを研究する
- スピノサウルスの尻尾の推進効率を 陸生動物と現存する水生脊椎動物と比較する
主な方法:
- Spinosaurus aegyptiacusの独特の尾の形状を分析し,高い神経の棘と長いシェブロンで特徴付けました.
- 物理的な尾のモデルによって生成される波動力を測定するロボットフラッピング装置を使用します.
- スピノサウルスの尾,地上の恐竜の尾,現存する水生脊椎動物の尾の推力と効率の比較分析.
主要な成果:
- Spinosaurus aegyptiacusは 独特の羽根のような尻尾構造を持ち 横向きに大きく動けていました
- スピノサウルスの尻尾の形は,陸上の恐竜の尻尾と比較して,水中の推進力と効率を大幅に高めました.
- スピノサウルスの尻尾の性能は 垂直に伸びた尻尾を泳いでいる 既存の水生脊椎動物と比べられます
結論:
- Spinosaurus aegyptiacusの独特な尾は 効果的な水中推進器官として機能しました
- これらの発見は,スピノサウルスの半水生生活様式を支持し,恐竜による水生環境のより広範な侵略を示唆しています.
- 水中の適応は,あまり顕著ではないが,他のスピノサウリド種にも存在し,このクラード内の重要な生態学的シフトを示している.
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