Exceptionally preserved 551-million-year-old site suggests Avalon biota lasted longer

Researchers studying the soft-bodied Ediacaran biotas of the world generally accept that there are three distinct assemblages. The 575–560-million-year-old (Ma) Avalon Assemblage is best known from the Ediacaran of Newfoundland, Canada, characterized by the weird and wonderful fractal Rangeomorpha like Charnia that thrived in the deep, dark waters around the ancient continent of Avalonia. The 560–550-Ma White Sea Assemblage is best known from shallow marine rocks of Australia, Russia, and China, marking the acme of Ediacaran biodiversity and including some famous animal ancestors such as Dickinsonia and Kimberella. And the 550–538-Ma Nama Assemblage is a low-diversity biota that persisted until the extinction event preceding the Cambrian Radiation event at 538 Ma.