脊椎動物の歯の起源と感覚外骨格の進化
Yara Haridy1, Sam C P Norris2, Matteo Fabbri2,3
1Department of Organismal Biology and Anatomy, The University of Chicago, Chicago, IL, USA. Yarah@uchicago.edu.
Nature
|May 21, 2025
まとめ
最も初期の歯の先駆者は 脊椎動物ではなく 節足動物です 歯骨は初期の脊椎動物で感覚外骨格組織として進化し,現在では最古の歯骨の証拠を代表する中期オルドビキアの化石がある.
科学分野:
- 古生物学
- 進化生物学
- 発達生物学
背景:
- 最古の歯の前身であるアナトレピス・ヘインツィの化石は,歯類のような管状で,早期の脊椎動物オドントードと異議を唱えた.
- アナトレピスの脊椎動物としての地位については,画像と比較組織分析によって制限された議論が続いた.
研究 の 目的:
- アナトレピスに関する論争を解決し,脊椎動物の歯の組織の進化的起源を明らかにする.
- オドントードと感覚構造の超構造的類似性と内置パターンを調査する.
主な方法:
- 多様な絶滅した,現存する脊椎動物と無脊椎動物の外骨格のシンクロトロンスキャン.
- 外骨格組織と超構造的特徴の比較分析
- 既存のコンドリキシアンとテレオストの免疫光分析.
主要な成果:
- アナトレピス管は誤って識別された. それは関節足の感覚器であり,歯骨ではない.
- オドントードと無脊椎動物の感覚構造に 超構造的な類似性がある.
- 脊椎動物のオドントドは,無脊椎動物のセンシルと収束し,感覚機能を示唆しています.
結論:
- 歯茎は脊椎動物の外骨格の感覚組織として発生した.
- 最も古い脊椎動物の歯の組織は カンブリア紀のアナトレピスの化石ではなく 中期オルドビカ紀のものです
- 現代の脊椎動物の歯は この祖先の感覚機能を保持しています
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