Reduction in Marine Primary Productivity in the Early Cambrian Nanhua Basin, South China.

The Cambrian explosion is represented by a rapid diversification of early animals in which the role of marine primary productivity remains obscure. In this study, we analyzed multiple geochemical data, including TOC, major, and trace elements, in the basinal Yuanjia section, South China. Covariations among TOC, P/Al, Cu, and Ni suggest that they could be taken as effective marine productivity proxies in the early Cambrian Nanhua Basin.

Uncovering the Ediacaran phosphorus cycle.

Phosphorus is a limiting nutrient that is thought to control oceanic oxygen levels to a large extent. A possible increase in marine phosphorus concentrations during the Ediacaran Period (about 635-539 million years ago) has been proposed as a driver for increasing oxygen levels. However, little is known about the nature and evolution of phosphorus cycling during this time.

Ediacaran Marine Redox Heterogeneity and Early Animal Ecosystems.

Oxygenation has widely been viewed as a major factor driving the emergence and diversification of animals. However, links between early animal evolution and shifts in surface oxygen levels have largely been limited to extrapolation of paleoredox conditions reconstructed from unfossiliferous strata to settings in which contemporaneous fossils were preserved. Herein, we present a multi-proxy paleoredox study of late Ediacaran (ca.