Terreneuvian Epoch

What happened during this time?

• No evidence of plants on the landscape

• The oldest evidence for freshwater environments (Geology, 2011)

• Burrowing animals are hypothesized to have stabilized Earth's oxygen levels during the Ediacaran-Cambrian transition (Boyle et al., 2014)

  • The evolution of the first burrowing animals significantly increased the extent to which oxygenated waters came into contact with ocean sediments. 

  • Exposure to oxygenated conditions caused the bacteria that inhabit such sediments to store phosphate in their cells.

  • This caused an increase in phosphorus burial in sediments that had been mixed up by burrowing animals, which, in turn, triggered decreases in marine phosphate concentrations, productivity, organic carbon burial, and ultimately, oxygen.

  • Because an oxygen decrease was initiated by something requiring oxygen (i.e., the activity of burrowing animals), a net negative feedback loop was created