The rise of animals occurred during an interval of Earth history that witnessed dynamic marine redox conditions, potentially rapid plate motions, and uniquely large perturbations to global biogeochemical cycles. The largest of these perturbations, the Shuram carbon isotope excursion, has been invoked as a driving mechanism for Ediacaran environmental change, possibly linked with evolutionary innovation or extinction. However, there are a number of controversies surrounding the Shuram, including its timing, duration, and role in the concomitant biological and biogeochemical upheavals. Here we present radioisotopic dates bracketing the Shuram on two separate paleocontinents; our results are consistent with a global and synchronous event between 574.0 ± 4.7 and 567.3 ± 3.0 Ma. These dates support the interpretation that the Shuram is a primary and synchronous event postdating the Gaskiers glaciation. In addition, our Re-Os ages suggest that the appearance of Ediacaran macrofossils in northwestern Canada is identical, within uncertainty, to similar macrofossils from the Conception Group of Newfoundland, highlighting the coeval appearance of macroscopic metazoans across two paleocontinents. Our temporal framework for the terminal Proterozoic is a critical step for testing hypotheses related to extreme carbon isotope excursions and their role in the evolution of complex life.

动物的崛起发生在地球历史的一段时期内，该时期见证了动态的海洋氧化还原条件，潜在的快速板块运动以及对全球生物地球化学循环的独特大扰动。这些扰动中最大的扰动是舒拉姆碳同位素偏移，它被用作驱动Ediacaran环境变化的机制，可能与进化创新或灭绝联系在一起。但是，关于Shuram的争议很多，包括时间，持续时间以及在伴随的生物和生物地球化学动荡中的作用。在这里，我们介绍了在两个独立的古大陆上把Shuram括起来的放射性同位素日期。我们的结果与574.0±4.7和567.3±3.0 Ma之间的全球同步事件一致。这些日期支持了这样一种解释，即Shuram是Gaskiers冰川化之后的一次主要同步事件。此外，我们的Re-Os年龄表明，加拿大西北部的Ediacaran大型化石的外观与纽芬兰构想组的类似大型化石在不确定的范围内是相同的，这突显了整个两个大洲的大型后生动物的同时期外观。我们用于末代元古代的时间框架是测试与极端碳同位素漂移有关的假设及其在复杂生命演化中的作用的关键步骤。纽芬兰构想小组的类似大型化石，强调了在两个古大陆上宏观后生动物的同时出现。我们关于元古代末期的时间框架是测试与极端碳同位素漂移有关的假设及其在复杂生命演化中的作用的关键步骤。来自纽芬兰构想小组的类似大型化石，突显了横跨两个古大陆的宏观后生动物的同时期出现。我们关于元古代末期的时间框架是测试与极端碳同位素漂移有关的假设及其在复杂生命演化中的作用的关键步骤。