哺乳類における多様な関節の収束進化

Fangyuan Mao^1,2, Shan Jiang^3,4, Jun Liu⁵

¹Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing, China. maofangyuan@ivpp.ac.cn.

Nature

|September 24, 2025

まとめ

哺乳類のの新たな関節を発見し哺乳類のの多様な進化の経路を明らかにしましたこれらの発見は,初期の哺乳類の祖先のの構造の多様化における繰り返し実験と生態学的要因を強調しています.

科学分野:

古生物学
進化生物学
比較解剖学

背景:

哺乳類のの進化は,単一歯骨と二次性関節によって特徴付けられ,重要な進化的革新である.
早期の哺乳類の関節構造の多様性を理解することで究極の哺乳類のへの移行について重要な洞察が得られます

研究の目的:

初期の哺乳類の関節構造の進化史と多様性を調査する.
哺乳類のの進化と多様化について新しい視点を提供するためです

主な方法:

2つの哺乳類の化石標本の分析:ポリストドン (トリチロドンチド) と初期のジュラ紀のモルガヌコドンタン.
これらの分類における二次関節構造の比喩的分析.

主要な成果:

独特の歯関節関節の発見ポリストドンジュラ紀中期の草食動物トリチロドンチド
初期のジュラ紀のモルガンヌコドンタンの球状コンディールが欠けていた歯状-状関節の特定,コンディール形成に関する仮説を裏付ける.
進んだシナドントにおける二次関節の独立した進化の証拠,哺乳類のシナポモルフィーとして歯関節がある.

結論:

多様な関節形態は,シノドントと哺乳類の進化実験を繰り返し示しています.
の筋肉の再編成,栄養の生態,そして噛む行動などの身体の縮小を超えた要因は,の関節の進化に影響を与えた.
生態学的多様性は,表型的な可塑性や環境的圧力が哺乳類の祖先の構造の形成に重要な役割を果たしたことを示唆している.

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