The ancestor of three significant animal species and a critical node in the evolutionary tree have been identified as a 518 million-year-old fossilised worm, according to a global team of experts from the Natural History Museum, the University of Oxford, and the University of Bristol. It is a bristly specimen that is just 1.2 centimetres long and a member of the extinct tommotiid family of mammals. It’s commonly known as Wufengella Bengtsoni.
Although these Cambrian shelly fossils have been found all across the world, very little is yet to be known about them. Wufengella, on the other hand, is proving to be a fascinating addition to the order.
It has asymmetrical armour enveloping a fleshy body dotted with spiny projections. Given its odd appearance, the worm may have once had a segmented body structure akin to an earthworm.
Brachiopods have a particular organ called a lophophore that allows them to filter water. Two other prominent members of the phylum, the phoronids (also known as horseshoe worms), and bryozoans, both have what is essentially a pair of tentacles folded into a horseshoe shape (called moss animals).
Animals are divided into more than 30 phyla, or classes. Each phylum’s members are distinguished from one another by a specific set of characteristics. Members of many phyla only share a small number of characteristics, which can be linked to the rapid rate of evolution that prevailed when these large groups first appeared. Approximately 550 million years ago, a time period known as the Cambrian explosion occurred.
Wufengella is a model species for the significance of the fossil record in reconstructing evolutionary trees, says co-author Greg Edgecombe from the Natural History Museum.
Owing to the very few anatomical characteristics that are shared by several phyla, looking just at living animals gives us an incomplete picture.
“With fossils like Wufengella, we can trace each lineage back to its roots, realising how they once looked altogether different and had very different modes of life, sometimes unique and sometimes shared with more distant relatives,” he claimed.