早期罗纪前类恐龙的胚胎及其进化意义
Robert R Reisz1, Diane Scott, Hans-Dieter Sues
1Department of Biology, University of Toronto at Mississauga, Mississauga, ON L5L 1C6, Canada. rreisz@utm.utoronto.ca
Science (New York, N.Y.)
|July 30, 2005
概括
新发现的Massospondylus carinatus胚胎揭示了早期恐龙的发展. 幼是四足的,与成年人不同,这表明后来的巨型足动物的进化途径和需要父母的照顾.
科学领域:
- 古生物学的古生物学
- 发展生物学 发展生物学
- 脊椎动物动物学 脊椎动物动物学
背景情况:
- 在南非的罗纪下期埃利奥特形成中,已经产生了有关节的恐龙胚胎.
- 像Massospondylus carinatus这样的普罗萨罗波德,代表了早期的恐龙血统.
- 了解本体遗传发展对于重建恐龙进化至关重要.
研究的目的:
- 通过使用胚胎化石来调查Massospondylus carinatus的本体遗传发展.
- 推断早期恐龙的运动和潜在的父母照顾需求.
主要方法:
- 分析了Massospondylus carinatus的关节胚胎化石.
- 胚胎和成人Massospondylus比例的比较解剖学.
- 重建胚胎的姿势和运动.
主要成果:
- 胚胎Massospondylus carinatus拥有大前肢和头部,子保持在水平位置,这表明幼必须是四足动物.
- 成年Massospondylus carinatus至少可以选择双脚.
- 胚胎特征表明可能需要父母的照顾.
结论:
- 马索斯邦迪勒斯·卡里纳图斯的本体发生表明,从四足的幼转变为任意双足的成年人.
- 这种发育模式可以透过四肢全度测量,提供关于巨型足动物四足的演变的见解.
- 早期的恐龙幼可能依赖于父母的照顾,因为它们的发育阶段和形态.
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