Fossils of giant predator worms, dubbed 'terror beasts', that lived more than 518 million years ago have been unearthed in North Greenland. The worms, named Timorebestia (Latin for 'terror beasts'), were some of the earliest carnivorous animals on Earth, according to scientists from the University of Bristol.
Growing to over 30cm in length, these worms had a distinct head, long antennae, massive jaws, and fins along their sides. They were among the largest swimming animals of the Early Cambrian period, over 520 million years ago. 'Timorebestia is a distant, but close, relative of living arrow worms, or chaetognaths, which are much smaller ocean predators today that feed on tiny zooplankton,' said study senior author Jakob Vinther.
These worms were giants of their time, near the top of the food chain. 'That makes it equivalent in importance to some of the top carnivores in modern oceans, such as sharks and seals back in the Cambrian period,' Dr Vinther added. The findings suggest ancient ocean ecosystems were more complex than previously thought, with a food chain accommodating several predator tiers.
In the fossilised digestive systems of the worms, scientists found remains of Isoxys, a common swimming arthropod of the time, indicating this was their main food source. Arthropods, including insects, appear in the fossil record about 521 to 529 million years ago. 'Both arrow worms and the more primitive Timorebestia were swimming predators. We can therefore surmise that in all likelihood they were the predators that dominated the oceans before arthropods took off,' Dr Vinther explained.
The discovery also sheds light on the origins of jawed predators in the ocean. More fossils from the expedition are expected to be unveiled in coming years, helping to unravel what the earliest animal ecosystems looked like and how they evolved. 'Over a series of expeditions to the very remote Sirius Passet in the furthest reaches of North Greenland, more than 82.5° north, we have collected a great diversity of exciting new organisms,' said Tae Yoon Park, another senior author from the Korean Polar Research Institute.
