“Terrifying Beast”: Researchers Share New Findings About Sea Worm With Antennas

Was the fearsome beast of the ancient sea a worm? Researchers examine fossils and share surprising results about the sea worm.

Bristol – Even long before animals fought their battles on land, there were animals that were clearly at the top of the food chain. These are perhaps less frightening than we imagine predators to be today. People also have a special place in the chain.

A research team was able to gain new insights using fossils from northern Greenland. A gigantic worm that devoured other sea creatures roamed the prehistoric oceans over 500 million years ago. The worm, named “Timorebestia koprii,” reached a length of up to 20 centimeters without antennae and even up to 30 centimeters with antennae, the team reported in the journal Science Advances explained.

Worm as a predator – 500 million years ago it dominated the food chain

The Latin name “Timorebestia” can be translated as “terrifying beast”. Scientists believe that this creature was one of the first predators. The Cambrian, the oldest period of the ancient world, stretched from around 540 to around 490 million years ago. The worm is said to have ruled here.

Because of their relatively impressive size, these prehistoric worms likely occupied a high position in the food chain. “This means they were just as important in the Cambrian as some of the largest predators in modern oceans, such as sharks and seals,” explains Jakob Vinther from the University of Bristol. He led the research team together with Tae-Yoon Park from the Korea Polar Research Institute in Incheon, South Korea.

“We already knew that primitive arthropods were the dominant predators in the Cambrian,” says Vinther. Before trilobites and other arthropods dominated the oceans, worms appear to have dominated them. At least this is suggested by the remains of extinct arthropods of the genus Isoxys, which were found in the stomachs of some of the 13 fossil specimens of Timorebestia koprii.

Prehistoric worm shows similarities to existing sea worms

With a resolution down to a thousandth of a millimeter via electron beam microanalysis, Vinther, Park and their team were able to visualize many of the mollusc's features. “Thanks to the remarkable, exceptional preservation in Sirius Passet, we can also reveal exciting anatomical details,” Park explains of the site, “including their digestive system, muscular anatomy and nervous system.”

What is particularly notable for them is a large nerve knot in the abdominal area. According to the researchers, the worm was probably an ancestor of modern arrowworms, which are now smaller and also live in the sea. The jaw structures of Timorebestia koprii indicate a relationship with the jaw mouths. These are marine worms that exist today and are about four millimeters long. “We have many more exciting findings to report in the coming years that will help reveal what the earliest animal ecosystems looked like and developed,” says Park.

Research was also able to find out more about prehistoric crocodiles. For example, they had skin similar to that of dolphins. An insect that was preserved by amber for 100 million years was also examined.

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