{"id":371950,"date":"2026-04-02T22:53:10","date_gmt":"2026-04-02T22:53:10","guid":{"rendered":"https:\/\/www.newsbeep.com\/il\/371950\/"},"modified":"2026-04-02T22:53:10","modified_gmt":"2026-04-02T22:53:10","slug":"jaw-dropping-fossils-reset-the-clock-on-when-complex-animals-evolved","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/il\/371950\/","title":{"rendered":"\u2018Jaw-dropping\u2019 fossils reset the clock on when complex animals evolved"},"content":{"rendered":"

April 2, 2026<\/p>\n

3 min read<\/p>\n

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\u2018Jaw-dropping\u2019 fossils reset the clock on when complex animals evolved<\/p>\n

A treasure trove of fossils from China shows that the Cambrian explosion may have been less explosive than scientists once believed<\/p>\n

By Jackie Flynn Mogensen<\/a> edited by Claire Cameron<\/a><\/p>\n

\"A<\/p>\n

A deuterostome cambroernid fossil and an artist\u2019s reconstruction of it. (The scale bar is two millimeters.)<\/p>\n

Around 540 million years ago, the ocean erupted with complex life: Creatures rapidly transformed from simple, soft-bodied, ocean-floor-dwelling animals into bodies we might recognize today\u2014animals with, say, a shell or cartilage, a mouth and anus, and the ability to swim, burrow or hunt.<\/p>\n

Scientists call this short, sharp burst of evolutionary activity the Cambrian explosion<\/a>, and it has informed the way we think about how life as we know it evolved on our planet. But the discovery of a trove of bizarre fossils in China is challenging that consensus\u2014the Cambrian explosion may have been less explosive than we thought.<\/p>\n

Hundreds of fossils uncovered in southern China\u2019s province of Yunnan reveal that at least some of the life-forms scientists had thought arose in the Cambrian period were alive and thriving millions of years earlier, in an era known as the Ediacaran period<\/a>. Many of the fossils look alien, from wormlike creatures tethered to the ground to a \u201csausage-shaped\u201d animal and a fingerlike organism with tentacles. The findings were published<\/a> in the journal Science on Thursday.<\/p>\n

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\"Sausage-shaped<\/p>\n

A newly discovered fossil of a sausage-shaped animal with an end-positioned mouth. (The scale bar is 2 mm.)<\/p>\n

The discovery was something of an accident, says Frances Dunn, a senior researcher of natural history at the Oxford University Museum of Natural History and a co-author of the paper. Her colleagues at Yunnan University in China found the trove while looking for algal fossils in the region\u2019s cliff faces\u2014its rocks are famous for their ability to preserve ancient life.<\/p>\n

This chance finding, Dunn says, turned out to hold \u201csome of the most significant early animal fossils\u201d found in decades. More than 700 specimens from the Ediacaran period were there. Some were mere algae, but hundreds more were animals that appeared in \u201ca variety of different forms,\u201d she says.<\/p>\n

The most common animal the team found was an organism about the size of a human adult index finger that had a wormlike body and a disk that kept it rooted to the seafloor. Its frequency\u2014more than 100 of the new specimens were examples of this unnamed creature\u2014suggests it once densely populated the ocean floor, Dunn says.<\/p>\n

\u201cIt was unlike anything I\u2019ve ever seen,\u201d Dunn says.<\/p>\n

\"wormy<\/p>\n

A reconstruction of life based on fossils found in the Chinese province of Yunnan dating to about 554 million to 539 million years ago.<\/p>\n

What was most jaw-dropping, however, was that so many of the found fossils looked uncannily like they belonged to the Cambrian period rather than the Ediacaran, she says. Some, including the abundant worm, were \u201cbilaterians.\u201d This term refers to animals with bilateral symmetry, or a body plan where one side mirrors the other. This critical evolutionary adaptation helped early life to move through sediment or the water column, develop a nervous system and eventually \u201cdominate\u201d the animal kingdom, Dunn says. Most animals today are bilaterians\u2014including humans.<\/p>\n

Before, scientists thought bilaterians primarily arose during the Cambrian period and were rare\u2014certainly not diverse and flourishing\u2014in the Ediacaran.<\/p>\n

The new fossils offer a glimpse into a \u201ctransitional world,\u201d where simple, soft-bodied life-forms lived alongside complex bilaterians. Some of the specimens look highly similar to cambroernids\u2014animals that looked vaguely similar to modern-day sea cucumbers\u2014which have previously only been dated to the Cambrian.<\/p>\n

\"A<\/p>\n

A nonbilaterian fossil (with a scale bar of 2 mm) and an artist\u2019s reconstruction of it.<\/p>\n

This is a once-in-a-lifetime find, Dunn says. \u201cPeople have been on the hunt for a fossil site like this but not found it until now,\u201d she adds. It indicates that the Cambrian \u201cexplosion\u201d may have been more gradual. Or, as Dunn puts it, the finding \u201cdefuses the Cambrian explosion.\u201d<\/p>\n

Now Dunn and her colleagues are working to formally describe all of the fossils and name any new creatures. Once everything has been cataloged, scientists can study where these animals fit on the tree of life.<\/p>\n

\u201cThe fossils from this site are going to keep us busy for like 10 years, easily,\u201d she says.<\/p>\n

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