近日，英国杜伦大学 Matthias Sinnesael的团队对摩洛哥西冈瓦纳地区寒武纪三叶虫的首现进行了贝叶斯天文年代学分析。该项研究成果发表在2024年1月8日出版的《地质学》上。

研究人员对Tiout剖面（摩洛哥）采集的一些最古老的三叶虫化石进行了天文年代学解释。研究提出了一个新方法，即，将单个天文周期持续时间纳入综合放射性同位素和天文年代学贝叶斯年龄深度模型，结果得出西冈瓦纳三叶虫首次出现的年龄预估约为519.62 Ma (95%最高后验分布为519.70-519.54 Ma )。这种精确的年龄估计水平对于深时生物事件来说是罕见的，同时，该研究也证明了新方法的优势。

据介绍，三叶虫在约ca. 520 Ma的首现是寒武纪大爆发的标志性特征。由于通常受到化石发现年龄及其全球地层对比的巨大不确定性的阻碍，解释早寒武世生命的进化没有强有力的支撑观点。

附：英文原文

Title: A Bayesian astrochronology for the Cambrian first occurrence of trilobites in West Gondwana (Morocco)

Author: Matthias Sinnesael, Andrew R. Millard, Martin R. Smith

Issue&Volume: 2024-01-08

Abstract: The first occurrence of trilobites at ca. 520 Ma is an iconic feature of the Cambrian Explosion. Developing a robust evolutionary view on early Cambrian life is generally hindered by large uncertainties in the ages of fossil finds and their global stratigraphic correlation. We developed an astrochronological interpretation for the Tiout section in Morocco that features some of the oldest trilobite fossils. Our novel approach to incorporating individual astronomical cycle durations in an integrated radioisotopic and astrochronological Bayesian age-depth model results in an age estimate of 519.62 Ma (519.70519.54 Ma 95% highest posterior distribution) for the first occurrence of trilobites in West Gondwana. This level of precise age estimation is exceptional for biological events in deep time and demonstrates the power of our novel approach.

DOI: 10.1130/G51718.1

Source: https://pubs.geoscienceworld.org/gsa/geology/article-abstract/doi/10.1130/G51718.1/632215/A-Bayesian-astrochronology-for-the-Cambrian-firstredirectedFrom=fulltext