从孤立的化石骨头中估计身体大小,揭示了北美的深度进化趋势
1Department of Integrative Biology and Museum of Paleontology, University of California, Berkeley, California, United States of America.
PloS one
|January 5, 2024
概括
研究人员开发了新的方法,从化石骨头中估计体积,揭示了古世的长度超过1米. 在古世后期,最大人体尺寸下降,独立于全球温度变化.
科学领域:
- 古生物学的古生物学
- 类学 类学 类学 类学
- 进化生物学 进化生物学
背景情况:
- 的古生态学和进化不太清楚,这是由于完整的化石记录的稀缺,大多数化石都是孤立的骨头.
- 目前对现存的研究很少测量单个骨头,这阻碍了与化石数据的比较和灭绝的体大小的重建.
- 之前的研究还没有确定皇冠群体的个体骨测量和身体长度之间的回归,也没有在化石骨上测试这些.
研究的目的:
- 开发新的方法来估计的身体大小 (鼻孔长度和质量) 从孤立的化石骨头使用现存的广泛数据集.
- 为了测试这个假设,解剖比例一直保持在更高层次的皇冠群体自古世以来保存.
- 重建北美西部内陆的体大小演变在古世时期 (66-2300万年前).
主要方法:
- 编制了一套广泛的数据集,包括来自皇冠分类组的现存的个体骨测量.
- 开发了回归方程,将个体骨测量与鼻孔孔长度 (SVL) 以及现存的体质相关联.
- 将这些新的回归方法应用于古世化石标本的大数据集,以估计身体大小.
主要成果:
- 个体骨测量显示,在现存和化石标本中,与SVL有很强的相关性 (R2 ≥0.69).
- 化石体大小估计揭示了中古时代最大的最大体型,一些焦虑超过1米SVL和1.5公斤.
- 的最大体型在古老时代晚期显著下降至400毫米以下和1.5公斤以下,与全球温度代理无关.
结论:
- 自古世以来,更高层次的皇冠群体内的解剖比例一直保持不变,使得从孤立的化石骨头可靠地重建身体大小.
- 这项研究提供了第一个深入的时间,大规模的地理调查体型进化跨群.
- 开发的方法提供了一种可靠的方法,可以从孤立的骨中估计身体大小,适用于任何冠状组,推进化石古生态学和进化研究.
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