脊椎微观结构标志着类恐龙在末大灭绝后不久的出现
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在PubMed上查看摘要
概括
此摘要是机器生成的。早期的海洋爬行动物被称为"鱼龙"在末期珀姆纪灭绝后迅速演变. 骨微观结构揭示了早期鱼类动物的生长模式和出生线, 显示了它们快速过渡到水生生物.
科学领域
- 古生物学
- 脊椎动物古生物学
- 进化生物学
背景情况
- 它是第一个完全适应海洋生物的四足动物, 发展了流线性身体, 翅膀和活产.
- 早期恐龙的进化路径和生态多样化仍然不清楚,特别是它们进入海洋环境的过渡.
研究的目的
- 通过脊椎骨微观结构研究鱼类的早期进化和生态转变.
- 记录已知最古老的恐龙胎儿化石并分析它们的遗传序列.
主要方法
- 两种早期三叠纪的脊椎骨微观结构的分析:Grippia (早期的鱼类) 和Cymbospondylus (鱼类).
- 组织学检查以比较骨结构,生长模式,并确定出生线.
- 基因组分为两部分,以了解鱼类类与鱼类类的转变.
主要成果
- 格里皮亚表现出独特的骨微观结构与紧的外层,而Cymbospondylus有无关节的脊椎,表明不同的生态和运动.
- 组织学上的差异表明Grippia和Cymbospondylus的生长速度不同.
- 第一个证据表明,鱼类的出生线被记录在案,同时也发现了快速生长的类鱼类.
结论
- 伊类恐龙迅速多样化,在末世大量灭绝后不到500万年出现了专门的形式.
- 这项研究捕捉了从类鱼类到类鱼类的生态和进化转变.
- 这一转变涉及生态和生理学的范式转变,促进了随后的恐龙辐射.
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