North Greenland has discovered fossils of giant predator worms known as “terror beasts” that colonized the water column over 518 million years ago. Timorebestia, which means “terror beasts” in Latin, was among the first carnivorous animals to inhabit the planet, according to researchers from the University of Bristol in the United Kingdom.
These worms, which could grow to be more than 30cm long and had a distinct head, long antennae, massive jaws, and fins down the sides of their body, were among the largest swimming animals during the Early Cambrian era over 520 million years ago.
What is Timorebestia, the terror beast discovered in Greenland?
“Timorebestia is a distant, but close, relative of living arrow worms, or chaetognaths. These are much smaller ocean predators today that feed on tiny zooplankton,” study senior author Jakob Vinther said.
According to the researchers, the worms, which were giants in their day, would have been 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 new findings suggest that ancient ocean ecosystems were more complex than previously thought, with a food chain that included multiple tiers of predators.
Scientists discovered remains of a common, swimming arthropod called Isoxys in the fossil digestive systems of the unearthed worm, implying that this animal group was their primary food source.
The latest discovery also sheds light on the origins of oceanic jawed predators
Arthropods, which include insects, first appeared in the fossil record around 521 to 529 million years ago.
Arrow worms, which date back at least 538 million years, are another common old animal fossil from the Cambrian era.
“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 latest discovery also sheds light on the origins of oceanic jawed predators.
More fossils from the expedition, which will be revealed in the coming years, are expected to help scientists understand 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,” Tae Yoon Park, another senior author of the study from the Korean Polar Research Institute, said.
“Thanks to the remarkable, exceptional preservation in Sirius Passet, we can also reveal exciting anatomical details, including their digestive system, muscle anatomy, and nervous systems,” Dr Park added.