ジュラ紀の新しい滑翔哺乳類
Qing-Jin Meng1, David M Grossnickle2, Di Liu1
1Beijing Museum of Natural History, Beijing 100050, China.
Nature
|August 10, 2017
まとめ
ジュラ紀後期から発見された2つの新しい滑り哺乳類は 樹木生活への早期適応を示しています これらの幹哺乳類は 滑りや寝るためのユニークな骨格の特徴を示し 初期の哺乳類の進化の洞察を提供します
科学分野:
- 古生物学
- 進化生物学
- 脊椎動物学
背景:
- 幹哺乳類はメソゾーイク時代の哺乳類の重要な初期の祖先を表しています.
- 彼らの研究は 哺乳類の歴史における 解剖学的進化と生態学的多様化の 重要な証拠を提供します
研究 の 目的:
- ジュラ紀後期から2つの新しい浮遊 (滑行) エレウテロドントの分類を記述する.
- 滑行や寝転がりに関する 骨格や皮膚膜の特徴を分析する
- 哺乳類内の遺伝的位置を決定し,現存する浮遊哺乳類との適応を比較する.
主な方法:
- 化石の発掘と骨格の分析
- 現在生息する脊椎動物と絶滅した脊椎動物を比較した解剖学的研究.
- 進化的関係を確かめるための 系統遺伝分析
主要な成果:
- 2つの新しいエレウテロドントの種が発見され,その中には滑り用の皮膚膜と,寝るための特殊な指も含まれている.
- これらの分類は,コウモリに似た,ウロパタジウムサポートのためのカルケナルカルカーを持っています.
- 系統遺伝学的な分析では,これらの飛翔形は樹木のエレウテロドントの中にあり,滑翔の収束進化を示しています.
結論:
- 滑翔するエレウテロドントは 移動における進化的実験を示し,袋類と胎盤類における 繰り返し滑翔する進化に並行する.
- これらの化石の固い鍵盤間構造は 鳥のと収束している.
- 滑動する際の肩帯の動きは,現代の滑動性有袋動物や胎盤動物とは異なるが,それと収束する.
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