[Rockhounds] 'Giant' predator worms more than half a billion years old discovered in North Greenland

[Kreigh Tomaszewski]

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.

"We have previously known that primitive arthropods were the dominant
predators during the Cambrian, such as the bizarre-looking
anomalocaridids," said Dr. Jakob Vinther from the University of Bristol's
Schools of Earth Sciences and Biological Sciences, a senior author on the
study. "However, 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."

"Our research shows that these ancient ocean ecosystems were fairly
complex, with a food chain that allowed for several tiers of predators."

"Timorebestia were giants of their day and would have been close to the top
of the food chain <https://phys.org/tags/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."
https://phys.org/news/2024-01-giant-predator-worms-billion-years.html