2026/06/22 by Chao Chang, Mingyu Zhao, Pengcheng Ju +12 · 1 voice
Earth and Planetary Sciences · #Ocean Acidification Effects and Responses #Paleontology and Evolutionary Biology #Paleontology and Stratigraphy of Fossils
paper · doi:10.1038/s41467-026-74516-9
openalex publication_date 2026/06/22 · openalex created_date 2026/06/23 · openalex updated_date 2026/07/23
Carbon dioxide is a fundamental atmospheric component that regulates Earth’s climate. However, atmospheric CO2 levels (pCO2) during the Cambrian Explosion remain poorly constrained. Here we report pCO2 variations reconstructed via carbon isotope signatures of algal fossils from eight fossil deposits across the Ediacaran–Cambrian transition (~553 to ~508 Ma). Results reveal an increase in pCO2 (±1σ) from ~3–9 to ~9–21 PAL during ~553–529 Ma, followed by a progressive decline to ~5–17 PAL and ~3–8 PAL at ~517 Ma and ~508 Ma, respectively. These temporal pCO2 changes coincide with shifts in marine strontium isotope values, which, together, are most consistent with tectonically driven changes in the carbon and strontium cycles, as supported by the results of Earth system biogeochemical box modelling. Tectonic modulation over a three-stage greenhouse–hypergreenhouse–greenhouse climate could have profoundly influenced marine environments in ways that impacted the early diversification of animals. This study reconstructs atmospheric CO2 variations during the Cambrian Explosion using algal carbon isotope signatures. It reveals a tectonically driven three-stage greenhouse-hypergreenhouse-greenhouse climate that impacted early animal evolution.