Nutrient flux and the evolutionary explosion across the Precambrian‐Cambrian boundary interval

Abstract

The “Cambrian explosion” in biosphere diversity was accompanied by major changes in sea level, the carbon cycle and phosphorus deposition. Carbon isotope excursions can be traced across Gondwana from China to Iran, as well as onto the Siberian Platform, and into Australia and Morocco. These isotopic excursions were contemporaneous with episodes of evaporite deposition and hydrocarbon burial in the Persian Gulf, Pakistan and Siberia, and followed by widespread salinity stratification. It appears likely that nutrient supply was affected by these changes. Differences in nutrient supply may explain the contrasting diversity and biomineralization patterns of phosphophilic invertebrates and oligotrophic archaeocyathan sponges through the early Cambrian.