China discovery pushes origins of complex life back millions of years

Newly found fossils from a site in southwestern China, preserved in exquisite detail, suggest that complex animals — perhaps even ancestors of all vertebrates — were around millions of years earlier than once thought.

The findings, published this week in the journal Science, stem from a time in Earth’s distant past called the Ediacaran era, which spanned approximately. 635 million to 542 million years ago, as reported in an article published by the University of Oxford.

A few types of creatures were previously known from the Ediacaran, but the evolution of complex animal life has long been associated with the Cambrian, a later period from 542 million to 488 million years ago, when fauna diversity and complexity were booming.

During the Cambrian explosion, animals with a wide range of bizarre structures and adaptations emerged. Some groups died out, but others eventually gave rise to modern animal groups such as chordates, crustaceans and molluscs.

As noted in the article, because the Cambrian fossil record preserves so much animal diversity, scientists have long hypothesised that complex animal life didn’t yet exist during the Ediacaran.

This latest find tells a different story, as these boneless organisms fossilised as biofilm. They were rapidly buried and compressed between layers of rock, leaving behind two-dimensional impressions of their organic tissues. Animals’ entire bodies were preserved, which means that feeding structures, delicate limbs and even traces of internal organs, which are typically lost during fossilisation, are still visible for researchers to explore.

This gave scientists the possibility, for the first time, to have highly detailed examples of animals from the latter part of the Ediacaran. What an international team of researchers saw suggests that complex animal life arose between 554 million and 539 million years ago — at least 4 million years before the Cambrian.

“We found what’s long been hoped for, which is a Cambrian-like preservation in the Ediacaran,” said study co-author Ross Anderson, an associate professor of natural history at the University of Oxford in the United Kingdom.

“We actually start to see some of the Cambrian-like organisms appearing in the Ediacaran when you have the right kind of preservation.”

Researchers found the fossils at the Jiangchuan Biota fossil site in what’s now China’s Yunnan province. Scientists from China and the UK excavated approximately 700 fossils during multiple visits between 2022 and 2025. About 200 of these specimens represented animals, many measuring less than 2.5 centimetres in length.

By Nazrin Sadigova