https://www.nature.com/articles/d41586-019-02556-x
https://media.nature.com/w800/magazine-assets/d41586-019-02556-x/d41586-019-02556-x_17129464.jpgThe fossil, which formed some time between 551 million and 539 million years ago, in the Ediacaran period, joins a growing body of evidence that challenges the idea that animal life on Earth burst onto the scene in an event known as the Cambrian explosion, which began about 539 million years ago.
“It is just pushing things further and further back into the Ediacaran,” says Rachel Wood, a geoscientist at the University of Edinburgh, UK. The Cambrian explosion no longer appears to be such an abrupt event in the history of life on Earth, she says.