Isotopic evidence for temperate oceans during the Cambrian Explosion.

ABSTRACT: The Cambrian Explosion was a key event in the evolution of life on Earth. This event took place at a time when sea surface temperatures have been proposed to reach about 60 °C. Such high temperatures are clearly above the upper thermal limit of 38 °C for modern marine invertebrates and preclude a major biological revolution. To address this dichotomy, we performed in situ δ¹⁸O analyses of Cambrian phosphatic brachiopods via secondary ion mass spectrometry (SIMS). The δ¹⁸O_phosphate data, which are considered to represent the most primary δ¹⁸O_seawater signature, were identified by evaluating the diagenetic alteration of the analyzed shells. Assuming ice-free conditions for the Cambrian ocean and no change in δ¹⁸O_seawater<

SUBMITTER: Wotte T 

PROVIDER: S-EPMC6474879 | biostudies-literature | 2019 Apr

REPOSITORIES: biostudies-literature