ジュラ紀のシュオテリドは哺乳類の最も初期の歯の多様化を示している
Fangyuan Mao1,2, Zhiyu Li3, Zhili Wang3
1Key Laboratory of Evolutionary Systematics of Vertebrates, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing, China. maofangyuan@ivpp.ac.cn.
Nature
|April 3, 2024
まとめ
古代の哺乳類であるシュウテリドは 独特のシドトリボスフェニック歯を持っていた. 新しい化石は,これらの歯がドコドントに同類であることを明らかにし,初期の哺乳類の進化を明らかにする新しいクラード,ドコドント型を形成しています.
科学分野:
- 古生物学
- 進化生物学
- 比較解剖学
背景:
- ジュラ紀の哺乳類であるシュウセリドは,セリアン哺乳類のトライボスフェニックパターンとは異なるシドートリボスフェニック歯を示している.
- シュオテリドの進化的起源と系統的配置は未だに十分に理解されていないため,早期の哺乳類の多様化に関する知識に影響を及ぼしている.
研究 の 目的:
- 新しく発見された化石標本を用いて,シュオテリドの歯の形状と遺伝的親和性を調査する.
- シュオテリドの歯の構造と他の哺乳類群との関係を再評価する.
主な方法:
- 2つの新しいジュラシクシュウテリド標本からの完全な歯の分析.
- シリアルホモロジーと歯の閉塞関係分析で 歯の構造を再特定する.
- 新しい形態学的証拠を組み込んだ 系統遺伝分析
主要な成果:
- シュオテリドの歯の構造はドコドントのそれと同類であり,以前の分類に異議を唱えている.
- シュオテリドはオスクトリボスフェニドから取り除かれ,ドコドンタンと新しいクラードであるドコドンティフォームにグループ化される.
- ドコドント型とホロテリアは 三角歯を持つ共通の祖先から独立して進化しました
結論:
- シュオテリドのシドトリボスフェニックパターンは,トリボスフェニックパターンとは異なる進化の経路を表している.
- ドコドンティフォームの確立は,哺乳類の初期の多様化と進化過程に関する新しい洞察を提供します.
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