来自温安生物群的埃迪亚卡兰大克隆诺菲克斯的发育生物学
Kirsten E Flett1, Kelsie Cracknell1, Johnny S Clavo Yamahuchi1
1Bristol Palaeobiology Group, School of Earth Sciences, University of Bristol, BristolBS8 1TQ, UK.
Biology letters
|March 12, 2026
概括
以前被认为是早期动物的温安生物化石显示异步细胞分裂,缺乏胃化. 这表明Megasphaera和Megaclonophycus是相同的生物体,挑战它们的动物亲和力和分子钟估计中的使用.
科学领域:
- 古生物学的古生物学
- 发展生物学 发展生物学
- 进化生物学 进化生物学
背景情况:
- 埃迪亚卡兰温安生物群包含微化石,被解释为早期动物胚胎.
- 在这个生物群中,Megasphaera和Megaclonophycus是占主导地位的种类,并提出了发展联系.
研究的目的:
- 通过使用先进的成像技术,研究巨星和巨克隆诺菲克斯之间的发育联系.
- 为了重新评估这些埃迪亚卡拉化石的元动物亲和力.
主要方法:
- 同步仪和计算机断层扫描被用来分析数百个Megaclonophycus标本.
- 量化了样本内的细胞数量和大小变化,以确定分裂模式.
主要成果:
- 巨和巨克洛诺菲克斯表现出类似的发育序列,大小和排列学,表明它们代表了同一生物体的不同生命阶段.
- 超大克隆诺菲克斯表现出异步的二进制细胞分裂,具有显著的细胞大小变异,缺乏胃流的证据.
- 在Megaclonophycus群中细胞数量大约在2048年和4096年左右,这与二进制减小分裂相一致.
结论:
- 这些发现与拟议的冠状组甲动物对Megasphaera和Megaclonophycus的亲和关系不相容.
- 对动物起源的分子钟估计不应该依赖Megaclonophycus作为校准点.
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