生态上不同的恐龙姐妹群体显示了Ornithodira早期的多样化
Sterling J Nesbitt1, Christian A Sidor, Randall B Irmis
1Lamont-Doherty Earth Observatory, Columbia University, Palisades, New York 10964, USA.
Nature
|March 6, 2010
概括
发现Asilisaurus kongwe,一个早期的鸟类系的类动物,揭示了Ornithodira和恐龙血统的古代起源. 这一发现凸显了三叠纪中期同期的鸟类系辐射与鱼系鱼类的辐射.
科学领域:
- 古生物学的古生物学
- 脊椎动物的进化 脊椎动物的进化
- 长龙类动物的遗传学 类遗传学
背景情况:
- 早期的Ornithodira (鸟类系的类动物) 由于像Lagerpeton这样的不完整化石和像类动物这样的专业形式,人们对它们的了解很少.
- 特里亚斯纪时期的类似于西莱索鲁斯的种类表现出彼此和恐龙之间的争论关系.
研究的目的:
- 为了描述一个新的鸟类系的类动物,Asilisaurus kongwe,来自坦桑尼亚的早期三叠纪中期.
- 为了确定Asilisaurus kongwe在Archosauria中的遗传学位置.
- 调查鸟类系类动物的早期多样化及其与恐龙的关系.
主要方法:
- 基于形态学数据的Asilisaurus kongwe的家族遗传学分析.
- 对骨特征,牙和推断的饮食与相关的种类进行比较分析.
主要成果:
- 阿西利萨乌鲁斯 (Asilisaurus kongwe) 被归类为一种鸟类系的类动物,也是恐龙的姐妹分类科Silesauridae的成员.
- 在三纪晚期,类动物表现出广泛的分布和多样性,具有独特的鸟类类植物结构.
- 牙和饮食的独立进化发生在从肉食祖先的silesaurids,ornithischians和sauropodomorphs中.
结论:
- 阿西利萨乌鲁斯 (Asilisaurus kongwe) 是已知最古老的鸟类系类动物,证实了Ornithodira和恐龙系的古老性.
- 中特里亚斯纪 (Anisian) 见证了鸟类系的类动物的同时辐射,与此前记录的鱼系类动物一起.
- 曼达古龙组合表明,在三纪中期或更早时期发生了显著的古龙多样化.
相关概念视频
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