一个坎布里亚中期的衣和鱼类的身体规划的深层起源
Karma Nanglu1, Rudy Lerosey-Aubril2, James C Weaver3
1Museum of Comparative Zoology and Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, 02138, USA. knanglu@fas.harvard.edu.
Nature communications
|July 6, 2023
概括
一个5亿年前的长袍化石,Megasiphon thylakos,揭示了早期的带动物进化. 这一发现表明,状成年阶段是长袍动物的祖先,影响了我们对脊椎动物起源的理解.
科学领域:
- 古生物学的古生物学
- 进化生物学 进化生物学
- 海洋生物学 海洋生物学
背景情况:
- 衣动物是进化上重要的海洋带动物,对于理解脊椎动物起源至关重要.
- 很少有人知道早期的长袍类动物的进化,包括它们的祖先息地 (海类和盆地类).
- 长袍化石记录稀少,软组织的保存有限.
研究的目的:
- 为了描述一个新的,保存得非常完善的长袍化石.
- 推断早期的长袍进化和体型设计的发展.
- 为了提供对衣动物的遗传位置的见解.
主要方法:
- 化石发现和描述Megasiphon thylakos nov.从马尔朱姆形成.
- 对化石特征的形态分析,包括气管和肌肉结构.
- 遗传学分析以确定化石在突尼卡塔的位置.
主要成果:
- 介绍梅加西 (Megasiphon thylakos) 的描述,这是一件5亿年前的长袍,具有桶形的身体和两个长的气管.
- 类似类动物的体型图案表明,双相生命周期 (浮游生物幼虫,静止成体) 可能是类动物的祖先.
- 这种化石支持了在坎布里亚时代爆发后早期建立关键的长袍体型特征的早期建立.
结论:
- 大西 (Megasiphon thylakos) 提供了早期形动物进化的关键证据.
- 这些发现支持一个坐位式的本体成年阶段作为Tunicata亚族的祖先.
- 这种化石挑战了现有的分子钟估计,并阐明了状动物早期的多样化.
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