A huge marine animal from the Early Cambrian Period has been discovered with strange facial appendages it used to filter food through.
The fossil of Tamisiocaris was discovered in northern Greenland during a series of recent expeditions led by co-author David Harper, a professor at Durham University.
It lived 520 million years ago, during the 'Cambrian Explosion', where all major animal groups and complex ecosystems suddenly appeared.
Tamisiocaris was a type of early arthropod and its feeding method is similar to how a blue whale feeds today – but with bizarre appendages on its face. It grew up to about 70cm in length, which although by modern standards is small, at the time it was one of the biggest creatures in the ocean.
Published in the journal Nature, lead author Jakob Vinther, from the University of Bristol, said: "These primitive arthropods were, ecologically speaking, the sharks and whales of the Cambrian era. In both sharks and whales, some species evolved into suspension feeders and became gigantic, slow-moving animals that in turn fed on the smallest animals in the water."
The creatures swam using flaps on either sides of their bodies. Their facial appendages in front of their mouths are believed to have been used to capture prey.
Researchers also found Tamisiocaris evolved suspension feeders that swept through the water like a net, trapping tiny animals for dinner.
Copenhagen University's Martin Stein, who created a 3D computer animation of the feeding technique, said: "Tamisiocaris would have been a sweep net feeder, collecting particles in the fine mesh formed when it curled its appendage up against its mouth. This is a rare instance when you can actually say something concrete about the feeding ecology of these types of ancient creatures with some confidence."
Vinther said that the discovery helps show how productive the Cambrian period was for evolution: "The fact that large, free-swimming suspension feeders roamed the oceans tells us a lot about the ecosystem. Feeding on the smallest particles by filtering them out of the water while actively swimming around requires a lot of energy – and therefore lots of food."
Tamisiocaris was one of many new species discovered in northern Greenland. David Harper, study co-author, said: "The expeditions have unearthed a real treasure trove of new fossils in one of the remotest parts of the planet, and there are many new fossil animals still waiting to be described. Our new understanding of this remarkable animal adds another piece to a fascinating jigsaw puzzle."