Episode 84: Neoproterozoic Acritarchs

Geology, as a subject, has for the most part assumed that there were no fossils to be found earlier than the Cambrian period. In the current day, we’re better-informed and are able to find good records of life before the Cambrian Explosion. Despite this, the structure of the Palaeocast website, with different pages for each period of the Phanerozoic Eon, shows we’re still biased against anything earlier than the Cambrian. We are guilty of lumping the majority of the evolution of life into the ‘Precambrian’: an Eon that represents the entire 4.6 billion year history of the Earth minus the 541 million years of the current Phanerozoic.

In this episode, we interview Dr Leigh Anne Riedman, University of California, about life during the Neoproterozoic Era, the most recent of the Precambrian Eon. This time interval is far from straight forward; not only were there changes in oceanic and atmospheric chemistry, but also dramatic shifts in climate and the formation and subsequent rifting of the supercontinent Rodinia. The Neoproterozoic also saw major biological innovations and ended with the appearance of the enigmatic Ediacaran Fauna.

Leigh Anne studies acritarchs, relatively simple, single-celled walled microorganisms and by examining their diversity and abundance, she is able to comment on how life fared during this turbulent time.