初期エオセンの哺乳類クリアカスの登山適応と,アルティオダクティラの起源

K D Rose

Science (New York, N.Y.)

|April 17, 1987

まとめ

ほぼ完全なクリアカスの骨格は,登山適応を明らかにし,アルティオダクティラの祖先としての提案された役割に挑戦しています. この初期のエオセンの哺乳類化石は,哺乳類の進化に関する重要な洞察を提供します.

科学分野:

パレオントロジー・パレオントロジー
哺乳類の進化について
初期のケノゾイク哺乳類初期のケノゾイク哺乳類

背景:

アークトコイオニドのクリアカスは,初期エオセンの哺乳類である.
以前の仮説では,クリアカス (Chriacus) や類似したアルクトシオニド (arctocyonids) がアルティオダクティラ (Artiodactyla) の祖先である可能性があると示唆されていた.

研究の目的:

最近発見された,例外的に保存されたクリアカスの標本の骨格の適応を分析するために.
形態学に基づいて,Artiodactylaとの関係でChriacusの系統遺伝的位置を評価する.

主な方法:

クリアカスのほぼ完全な関節骨格の詳細な骨格学的分析.
クリアカスの骨格の特徴を,初期のエオセンの哺乳類とアルティオダクティラと比較した形態学的評価.

主要な成果:

クリアカスの骨格は,強力な筋肉,前腕のサピネーション,移動可能な足首,プランティグラード足,曲がった爪,長い尻尾を含む,登りのための数多くの適応を示しています.
これらの樹木の適応は,既知の最も古いアーティオダクティルの形態学とは異なる.

結論:

Chriacusの特殊な登山適応は,Artiodactyla.の祖先ではなかったことを示している.
この発見は,以前の系統遺伝学的な提案を否定し,初期エオセンの哺乳類のライフスタイルの多様性を強調しています.

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