トライアスのダイアプシドは,爬虫類の皮膚付属体の初期の多様化を示している
Stephan N F Spiekman1, Christian Foth2,3,4, Valentina Rossi5,6
1Staatliches Museum für Naturkunde Stuttgart, Stuttgart, Germany. stephanspiekman@gmail.com.
Nature
|July 23, 2025
まとめ
化石の爬虫類ミラサウラ・グレイヴォジェリは 胎児の歴史の初期に 進化した複雑な体付属体を明らかにしている. これらの構造は鳥や哺乳類より前に存在し 爬虫類のの進化に関する現在の理解に 挑戦しています
科学分野:
- 古生物学
- 進化生物学
- 脊椎動物学
背景:
- テトラポッドの進化には 羽毛や毛のような 複雑な帯が不可欠です
- 彼らの遺伝子規制ネットワークは 深い胎児の根源を持っていますが 初期の進化は 化石の証拠が不足しているため 十分に理解されていません
研究 の 目的:
- 胎児の付属体の初期進化を調査する
- 新発見のトライアス紀の爬虫類 ミラサウラ・グレイヴォゲリの 形態学と系統学を分析する
主な方法:
- Mirasaura grauvogeliの化石の考古学的な発掘と分析
- 膜付属体内の保存されたメラノソームの顕微鏡検査
- Mirasaura grauvogeliの進化的関係を決定する 系統遺伝分析
主要な成果:
- ミラサウラ・グレイヴォゲリ (Mirasaura grauvogeli) は中期トライアシックのダイアプシドで,長身の付属体の頂部を持っていた.
- 保存されたメラノソームは羽毛に似ていますが,付属体は羽毛や毛に同型ではありません.
- ミラサウラは,現存する爬虫類に基礎的なクラードであるドレパノサウルモルファに属している.
結論:
- 鳥や哺乳類より前の産卵系で 複雑な膜付属体が進化した.
- この発見は,複雑な付属体のアベメタタサリアンと哺乳類との排他的な関連に異議を唱える.
- この発見は,爬虫類のの進化の理解を 修正する必要がある.
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