ジュラ紀のエウハラミイダンの3つの新しい種は,哺乳類の早期の分岐を強めている
Shundong Bi1, Yuanqing Wang2, Jian Guan3
11] Key Laboratory of Vertebrate Evolution and Human Origins of Chinese Academy of Sciences, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing 100044, China [2] Department of Biology, Indiana University of Pennsylvania, Indiana, Pennsylvania 15705, USA.
Nature
|September 12, 2014
まとめ
ニュージュラ紀の化石は,絶滅したクラードであるEuharamiyidaを明らかにし,哺乳類の進化を明らかにしています. これらの発見は,アロテリアを哺乳類の中に配置し,ラウラシアの哺乳類のトリアシク後期起源を示唆しています.
科学分野:
- パレオントロジー・パレオントロジー
- 進化生物学の進化生物学について
- 哺乳類の進化について
背景:
- アロテリア (MultituberculataとHaramiyida) と哺乳類の起源の間の進化的関係については,ほとんど理解されていません.
- 過去の研究は,早期哺乳類の進化について矛盾する見解を生み出しました.
研究 の 目的:
- アロテリアの系統形成と哺乳類の最古の進化を調査する.
- 新しいクラードであるEuharamiyidaとその化石の証拠を記述するために.
主な方法:
- 中国の6つの保存状態が良好なジュラ紀の化石の系統遺伝分析.
- ユーハラミイドンの頭蓋骨歯と頭蓋骨の後部部部位の詳細な調査.
主要な成果:
- クラードEuharamiyida.に属する3つの新しい種の特定.
- Euharamiyidaは,Multituberculataの姉妹グループとして認識されており,AllotheriaはMammaliaの中に巣を構えている.
- 証拠によると,アロテリアン哺乳類は,ハラミアヴィアのようなトライアシク後期の祖先から生まれたことを示唆しています.
結論:
- この研究は,哺乳類内のAllotheriaの位置と,euharamiyidansとmultituberculatesの進化的分岐を明らかにしています.
- 発見は,ラウラシアにおける哺乳類のトリアシク後期起源を支持する.
- 哺乳類の進化の過程で,中耳の2つの独立した骨脱離が推論されている.
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