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最早的胚胎痕迹重新校准了四足动物进化的时间线
John A Long1, Grzegorz Niedźwiedzki2,3, Jillian Garvey4,5
1College of Science and Engineering, Flinders University, Adelaide, South Australia, Australia.
Nature
|May 14, 2025
概括
新的澳大利亚化石痕迹表明,皇冠群羊起源于早期的石灰岩时期,将它们的起源推迟了3500万至4000万年,并表明四足动物进化的更深层次的德沃纪根源.
科学领域:
- 古生物学
- 进化生物学
- 平面图学
背景情况:
- 已确立的化石记录显示,皇冠群羊的起源是在碳纪晚期,四足动物的起源是在碳纪中期.
- 之前的理解表明四足动物冠群起源于早期碳期 (早期图尔纳斯期) 和后期碳期的羊.
研究的目的:
- 来自澳大利亚的新轨道数据挑战了早期胚胎和四足动物进化的传统时间表.
- 根据新的化石证据重新评估冠状四足动物和羊动物的起源日期.
主要方法:
- 来自澳大利亚维多利亚州雪地平原形成的轨道承载地质板块的分析.
- 精确的约会化石板块到早期的Tournaisian时期.
- 一个有爪子,冠状组胚胎的足迹的识别, 可能是原始的类动物.
主要成果:
- 澳大利亚的痕迹,可以追溯到早期的Tournaisian,表明皇冠组胚胎的起源至少比以前认为的要早3500万年.
- 这些发现表明,胚胎冠状组节点可以追溯到德/碳化时期的边界附近.
- 据推断,四足动物冠群节点比较古老,可能起源于德纪早期的弗拉斯尼纪阶段.
结论:
- 早期碳化时期的轨道证据显著修订了羊和四足动物进化的时间表.
- 所有的干四足动物和干羊动物的血统都可能起源于纪.
- 四足动物的进化可能更快,而德纪四足动物化石记录可能比目前理解的更不完整.
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