一个关于恐龙关系和早期恐龙进化的新假设
Matthew G Baron1,2, David B Norman1, Paul M Barrett2
1Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EQ, UK.
Nature
|March 24, 2017
概括
一个新的恐龙家族树表明Ornithischia和Theropoda是密切相关的,形成了Ornithoscelida类. 这对早期恐龙进化的长期观点提出了挑战,需要重新分类主要的恐龙群体.
科学领域:
- 古生物学
- 进化生物学
- 系统性研究
背景情况:
- 恐龙在历史上被分为两个主要类型:Ornithischia和Saurischia.
- 这种传统的分类已经达成共识了130年.
- 目前的克拉迪斯定义在理解早期恐龙进化方面存在挑战.
研究的目的:
- 提出主要恐龙群体之间的基因关系的新假设.
- 挑战关于早期恐龙进化的现有共识.
- 解决当前克拉迪斯定义中的问题.
主要方法:
- 主要恐龙群的遗传学分析.
- 开发一种新的进化树拓.
- 恐龙类的克拉迪斯基重新定义和诊断.
主要成果:
- 在Ornithischia和Theropoda之间发现了姐妹群关系,形成了一个新的分类:Ornithoscelida.
- 类动物和类动物 (重新定义为类动物) 构成了类动物的单体外群.
- 这种新的拓需要重新评估早期恐龙的克拉多生成和特征进化.
结论:
- 拟议的Ornithoscelida类挑战了传统的恐龙分类.
- 建议在类动物和类动物中独立获得超肉食性.
- 这种新型的基因组解释了先前已知类动物和早期鸟类之间的解剖学趋同.
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