坎布里亚时代的碳化原始类动物和Chaetognatha的早期化石记录
1Department of Earth Sciences, Palaeobiology, Uppsala University, Uppsala, Sweden.
Proceedings. Biological sciences
|February 19, 2025
概括
早期的坎布里亚化石称为protoconodonts,作为小型碳化化石 (SCFs) 保存,揭示了chaetognaths的古代起源. 这些SCF提供了一种新的方法来研究早期的双边进化,比以前已知的化石证据更早.
科学领域:
- 古生物学的古生物学
- 进化生物学 进化生物学
- 早期生活研究 早期生活研究
背景情况:
- 对于早期坎布里亚河类动物的化石证据是有限的,主要是在特定的 Lagerstätten 遗址上以分散的化抓棘 (protoconodonts) 的形式发现.
- 最近的遗传学研究表明,chaetognaths与Gnathifera类相关,突出了早期进化校准点的需要.
- 小碳化化石 (SCF) 代表了研究早期动物起源的未充分利用的化石保存类型.
研究的目的:
- 描述从早期的坎布里亚泥石中作为小碳化化石 (SCF) 保存的原始.
- 评估SCF作为追踪Chaetognatha进化起源的资源的实用性.
- 为了确定深层双边基层的分歧的校准点,包括Gnathifera.
主要方法:
- 从爱沙尼亚和瑞典的Fortunian和Stage 4泥岩中提取和分析作为SCF保存的原始.
- 将SCF保存与传统研究的酸原生动物进行比较.
- 编制现有的SCF原生的记录,以重建进化时间线.
主要成果:
- 作为SCFs保存的丰富的原始鱼从早期的坎布里亚泥石中恢复,提供了大量的保存.
- SCFs在常见的海洋类沉积物中发现,与稀缺的性原生不同.
- 像Chaetognath这样的双边生物可能在最新的Ediacaran (555545 Ma) 进化,皇冠组下巴复合体至少在520 Ma出现.
结论:
- 小碳化化石提供了一个有价值的,被忽视的资源,以了解chaetognaths和其他双边类的早期进化.
- 这些发现将众所周知的chaetognath类生物的进化时间线推回到埃迪亚卡拉时期.
- 这项研究为深度双边分歧建立了关键的校准点,包括Protostomia,Lophotrochozoa和Gnathifera.
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