该团队提出了内华达州下伍德峡谷地层的精确锆石U-Pb年龄。这些数据表明，根据遗迹化石生物地层学和碳同位素化学地层学定义，寒武纪的基底比533 Mya更年轻，至少比目前公认的的晚6 My。这种新的地质年代学凝结了以前的Nemakit-Daldynian(寒武纪早期)年龄模型，结合全球纪录，展示了爆炸性的现代动物门的早期辐射节奏。
据了解，寒武纪地层中现代动物化石在地质学上的迅速出现是地球生命史的一个决定性特征。然而，寒武纪底部的时间校准在数百万年内仍然不确定，这导致了对离散寒武纪爆发概念的不断挑战。
附：英文原文
Title: Cambrian explosion condensed: High-precision geochronology of the lower Wood Canyon Formation, Nevada
Author: Nelson, Lyle L., Crowley, James L., Smith, Emily F., Schwartz, Darin M., Hodgin, Eben B., Schmitz, Mark D.
Issue&Volume: 2023-7-17
Abstract: The geologically rapid appearance of fossils of modern animal phyla within Cambrian strata is a defining characteristic of the history of life on Earth. However, temporal calibration of the base of the Cambrian Period remains uncertain within millions of years, which has resulted in mounting challenges to the concept of a discrete Cambrian explosion. We present precise zircon U–Pb dates for the lower Wood Canyon Formation, Nevada. These data demonstrate the base of the Cambrian Period, as defined by both ichnofossil biostratigraphy and carbon isotope chemostratigraphy, was younger than 533 Mya, at least 6 My later than currently recognized. This new geochronology condenses previous age models for the Nemakit–Daldynian (early Cambrian) and, integrated with global records, demonstrates an explosive tempo to the early radiation of modern animal phyla.
DOI: 10.1073/pnas.2301478120
Source: https://www.pnas.org/doi/10.1073/pnas.2301478120