The ancestral monster of three living animal lineages has been sealed within a rock in China, preserving astonishingly intact features.
According to Sci-News, the small creature Wufengella bengtsoni, resembling a spiky armored mace, was an extinct worm that lived during the Cambrian period.
It resided in what is now China around 518 million years ago and belongs to an ancient group known as tommotiids. Despite its small size, measuring only 1.3 cm, it is regarded as the “great ancestor” of three major groups of organisms that are widespread across the Earth today.
The natural “relief” on a rock in China offers immense value to paleontology – (Image: Current Biology)
“It looks like a bizarre hybrid between a fuzzy caterpillar and a mollusk. Interestingly, it belongs to neither group,” said Dr. Jakob Vinther from the School of Earth Sciences at the University of Bristol, a member of the multinational research team.
The remarkably well-preserved specimen of this previously unknown species unearthed in China even helped scientists identify the tiny, flat lobes protruding from either side of its armor, which are the attachment points for its bristles. Numerous lobes, bristles, and shell plates on its back provide evidence that this worm was originally segmented, similar to a modern earthworm.
The animal kingdom comprises over 30 major body plans, each containing a unique set of features that distinguish them from one another.
This creature exhibits several characteristics shared with many of the aforementioned groups, demonstrating the rapid pace of evolution, as it is one of the originators and a common ancestor of many species.
Reconstructed portrait of the small monster – (Image: Current Biology).
It also possesses characteristics that establish it as an ancestor of the Lophophorata, a common group that includes horseshoe worms and tiny moss animals found abundantly in oceans.
This half-billion-year-old worm is also an ancestor of the phylum Brachiopoda, a group of organisms resembling clams that live attached to the sea floor and coral reefs.
Its third lineage is even more prominent – the arthropods. “For a long time, biologists have noted that arthropods have multiple paired body segments, unique renal structures, and bristles on their backs when they are still larvae,” Dr. Vinther added.
Arthropods, also known as jointed-legged animals, encompass over 1 million different species ranging from tiny mites to various insects, making them one of the most diverse groups on Earth. The connection of their ancestors to bizarre aquatic species from the ocean is truly astonishing.
Thus, this valuable fossil has become a rare and unexpected piece that helps fill a crucial gap in the evolutionary tree of life on Earth.
The research has just been published in the scientific journal Current Biology.
