Fossils of a new group of animal predators have been located in the Early Cambrian Sirius Passet fossil locality in North Greenland. These large worms may be some of the earliest carnivorous animals to have colonized the water column more than 518 million years ago, revealing a past dynasty of predators that scientists didn't know existed.

The new fossil animals have been named Timorebestia, meaning 'terror beasts' in Latin. Adorned with fins down the sides of their body, a distinct head with long antennae, massive jaw structures inside their mouth, and growing to more than 30cm in length, these were some of the largest swimming animals in the Early Cambrian times.