雌の恐竜の体内にある,貝殻を外した卵のペア

Tamaki Sato¹, Yen-nien Cheng, Xiao-chun Wu

¹Canadian Museum of Nature (CMN), Post Office Box 3443, STN D, Ottawa, Ontario K1P 6P4, Canada. tsato@mus-nature.ca

Science (New York, N.Y.)

|April 16, 2005

まとめ

オービラプトサウルスの恐竜はペアで卵を産み,その生殖戦略の直接的な証拠を提供した. この発見は,セロポッド恐竜が2つの卵管を持ち,鳥のように連続して卵を産んだことを示唆している.

科学分野:

パレオントロジー・パレオントロジー
生殖生物学生殖生物学
恐竜族 (Dinosauria) とは

背景:

オビラプトロサウル類の恐竜は,白亜紀期からの多様なセロポッド群である.
絶滅した恐竜の生殖戦略は,しばしば化石の証拠から推測される.
以前の研究では,セロポッドの様々な巣立ったり卵を産んだりする行動が示唆されていた.

研究の目的:

オビラプトロサウルスの恐竜の産卵の直接的な証拠を提供するために.
化石化した卵に基づいて,セロポッド恐竜の生殖生理学と行動を推論する.
オビラプトロサウルスの生殖解剖学と現代の鳥やワニの生殖解剖学との関係を調査する.

主な方法:

中国の上白亜紀の化石化したオビラプトサウルスの標本の調査.
標本の骨盤領域に留まった2つの貝殻のない卵の分析.
既存のアーコサウルス (鳥やワニ) と化石の卵殻データ (長方形の卵) の比較解剖分析.

主要な成果:

独特のオビラプトサウルスの標本が発見され,その骨盤には2つの無傷で,殻を外した長方形の卵が発見されました.
この発見は,オービラプトロサウルスがペア化した卵を産んだという最初の直接的な証拠を提供します.
卵の配置は,セロポッドには2つの機能的な卵管があり,卵管ごとに一度に1個の卵を産み,クラッチは複数の巣を作るイベントにわたって置かれることを示唆しています.

結論:

熱足類恐竜,特にオビラプトロサウルスは,現代のワニに似た2つの機能的な卵管を有していた可能性が高い.
熱足類の産卵は,連続した卵置立を伴う可能性があり,現代の鳥類に似た複数の巣作りのイベントを通じてクラッチが完成した.
標本内および関連クラッチの卵の向きは,母が卵を産むために巣の中心に近づいたことを示しています.

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