恐竜の体温は,化石バイオミネラルの同位体 (13C-18O) 順序から決定される
Robert A Eagle1, Thomas Tütken, Taylor S Martin
1Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA. rob.eagle@gmail.com
Science (New York, N.Y.)
|June 25, 2011
まとめ
凝集型同位体温度測定により,ジュラ紀のサウロポッド恐竜は,哺乳類に似た36~38°Cの体温を持っていたことが明らかになった. これは,これらの巨大な動物には,内部温度を調節するメカニズムがあった可能性があることを示唆しています.
科学分野:
- パレオントロジー・パレオントロジー
- 温度調節 温度調節 温度調節 温度調節
- イソトープ地球化学 イソトープ地球化学
背景:
- 非鳥類の恐竜の代謝生理学と熱調節は,科学的な議論の対象であり続けている.
- 以前の研究では,様々な方法論に基づいて,内熱 (熱血) と外熱 (冷血) 代謝の両方について議論を提示しました.
研究 の 目的:
- 新しい温度測定法を用いて,大きなジュラサイクスのサウロポッドの体温を調査する.
- 恐竜の生理学と熱調節に関する進行中の議論に経験的データを寄与する.
主な方法:
- 凝集型同位体温度計 (clumped isotope thermometry) は,鉱物の同位体比を分析する地化学的手法である.
- この方法を適用して,大きなジュラサイクスのサウロポッドの化石化した歯の化学組成を分析した.
主要な成果:
- 研究されたサウロポッドの体温は36°Cから38°Cの範囲であった.
- これらの気温は,現代の哺乳類で観察されたものと比較できます.
- 測定した気温は,恐竜の体温に関する質量依存スケーリングモデルによって予測されたより4°Cから7°C低い.
結論:
- サウロポッドは,おそらく巨大な体量のために,過熱を防ぐための生理学的メカニズムを有していた.
- この発見は,大型恐竜の複雑な温度調節戦略を示唆し,単純な質量依存予測とは異なる.
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