概括
来自北美和非洲的罗纪早期陆地脊椎动物化石揭示了新的相关性. 这一发现挑战了在罗纪-罗纪边界发生重大四足动物灭绝事件的想法.
科学领域:
- 古生物学的古生物学
- 在平流体学上,平流体学是平流体学.
- 脊椎动物的进化 脊椎动物的进化
背景情况:
- 三亚纪-罗纪的边界传统上被认为是四足动物大量灭绝的时期.
- 之前对跨大陆岩层的相关性已被用来定义这个边界.
- 纽瓦克超级群 (美国东部),格伦峡谷群 (美国西南部) 和斯托默伯格群 (非洲南部) 是关键的化石载体.
研究的目的:
- 重新评估来自纽瓦克超级群,格伦峡谷群和斯托姆伯格群的关键陆地脊椎动物化石集合的年龄.
- 为了在这些南半球和北半球形成之间建立一个更准确的时间层级图相关性.
- 为了测试在罗纪-罗纪边界发生广泛四足动物灭绝事件的假设.
主要方法:
- 在指定的地质群体内分析陆地脊椎动物化石的发生情况.
- 基于已确定的化石范围的生物层级测年法.
- 使用化石证据,在不同大陆的地质层的相关性.
主要成果:
- 陆地脊椎动物化石表明,纽瓦克超级群的部分部分和格伦峡谷群的全部是罗纪早期的.
- 南非的上风暴山群也被证实是罗纪早期的.
- 这些发现为这些岩石单元建立了一个新的时间层级图框架.
结论:
- 以前推断的三纪-罗纪边界的四足动物大规模灭绝是不准确的相关联的工件.
- 化石记录表明,陆地脊椎动物在罗纪-罗纪的边界上更为渐进的过渡.
- 这一修订的相关性提供了更强大的理解脊椎动物在这个关键时期的进化.
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