甲时期的鸟类支持一个新鸟的祖先
Juan Benito1, Pei-Chen Kuo2, Klara E Widrig2
1Department of Earth Sciences, University of Cambridge, Cambridge, UK. jb2284@cam.ac.uk.
Nature
|November 30, 2022
概括
一种新的化石鸟, Janavis finalidens, 显示了与现代水鸟和陆鸟相似的口腔结构. 这一发现表明这种口腔类型可能是所有鸟类的祖先, 挑战了关于早期鸟类进化的先前假设.
科学领域:
- 古生物学
- 进化生物学
- 比较解剖学
背景情况:
- 骨的区分了主要的鸟类群:新 (未合的,动力头骨) 和古 (合的,刚性头骨).
- 长期以来,Paleognathae的合口腔被认为是冠状鸟类 (Neornithes) 的祖先.
- 早期尼奥尼丁口腔的化石证据很少,限制了对祖先特征的理解.
研究的目的:
- 为了研究皇冠鸟 (Neornithes) 的祖先的口腔状况.
- 重新评估关于早期鸟类口味演变的长期假设.
- 澄清中生代鸟类的遗传位置及其口腔形态.
主要方法:
- 一个新化石分类的描述和分析, Janavis finalidens,从白纪晚期.
- 与现存的鸟类类 (Neognathae,Paleognathae) 和其他化石种类进行了贾纳维斯口腔的比较形态分析.
- 将Janavis纳入现有的鸟类进化框架的基因分析.
主要成果:
- Janavis finalidens 具有与现存的新鸟类,特别是 Galloanserae (水鸟+陆鸟) 非常相似的状骨头.
- 贾纳维斯是除了伊希奥尼斯外,也是第一个代表伊希奥尼斯的成员,证实了该类的持续存在到最后的白纪.
- 这些发现表明中生代非冠状鸟类中存在解剖学新的口腔,这表明这可能是冠状鸟类的形特征.
结论:
- 贾纳维斯的口腔结构挑战了合口腔是皇冠鸟的祖先的假设.
- 像现存的Galloanserae一样的形形态可能是冠状鸟类的形形态.
- 这些结果需要重新评估早期纪鸟类群体的进化关系和亲属关系,如鸟类.
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