A 518 million-year-old fossil of an armored worm has been discovered in China that may be the long-sought ancestor of three large groups of living animals, including many aquatic invertebrates.
The discovery is due to an international group of researchers led by the Chinese Yunnan University, who have published the results of their analyzes in the journal Current Biology.
The find highlights the importance of fossils in reconstructing evolution, since it dates back to a period shortly after the so-called 'Cambrian Explosion' of 550 million years ago, which saw the sudden appearance of most of the complex animals. .
"When we realized what the fossil we were looking at under the microscope was, I couldn't believe my eyes," comments Luke Parry of the British University of Oxford, one of the authors of the study led by Jin Guo: "This is a fossil that we have at long imagined and hoped to be able to see with our eyes ".
The ancient armored worm, called Wufengella, measured just over a centimeter and was a squat creature covered on its back by a dense array of overlapping plates.
On the hips, on the other hand, bundles of bristles emerged starting from a body formed by a series of segments, like that of an earthworm.
“If we look only at living animals, we get an incomplete picture,” comments Gregory Edgecombe of the Natural History Museum in London, co-author of the study.
"With fossils like Wufengella we can trace every lineage back to its roots and we see that, once upon a time, animals looked completely different and had different lifestyles, sometimes unique and sometimes shared with more distant relatives."
