518-Million-Year-Old 'Terror Beasts' Unearthed in North Greenland

The newly discovered Timorebestia, giant predatory worms, provide new insights into early ocean ecosystems and the evolution of arrow worms.

Fossils of a new group of animal predators, named Timorebestia, have been discovered in the Early Cambrian Sirius Passet fossil locality in North Greenland.
These large worms, over 30cm in length, may be some of the earliest carnivorous animals to have colonised the water column more than 518 million years ago.
Timorebestia is a distant relative of living arrow worms, or chaetognaths, much smaller ocean predators today that feed on tiny zooplankton.
Inside the fossilised digestive system of Timorebestia, the researchers found remains of a common, swimming arthropod called Isoxys, indicating a complex food chain with several tiers of predators.
The discovery of Timorebestia provides new insights into the evolution of arrow worms and the early animal ecosystems.