The discovery of new fossils in northern Greenland revealed that a 520-million-year-old sea creature used its appendages to filter plankton, similar to the way modern blue whales feed today.

The fossils belonging to the strange species called Tamisiocaris were discovered by a team of University of Bristol researchers.  The researchers speculate that the animal lived during the Early Cambrian period, also known as the 'Cambrian Explosion', in which all the major animal groups and complex ecosystems suddenly appeared.

The newly discovered fossils provide evidence that the animal grew limbs that transformed their grasping appendages into filters that could trap organisms in the water like a net.

"Tamisiocaris would have been a sweep net feeder, collecting particles in the fine mesh formed when it curled its appendage up against its mouth," Martin Stein of the University of Copenhagen said in a statement. "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."

Researchers created a 3D computer animation of the creature's feeding appendage to help them better its anatomy.

Tamisiocaris belongs to a group of animals called anomalocarids, which were some of the first predators on Earth. Although it measured just 28 inches long, Tamisiocaris was one of the largest predators in the world when it was in existence.

"It was a gentle giant," paleontologist and study leader Jakob Vinther of the University of Bristol told Reuters. "Even though this thing was not a whale or a whale shark, it evolved to become the equivalent."

Most anomalocarids fossils have been found in the Burgess Shale, a fossil-rich site in the Canadian Rockies.

"We once thought that anomalocarids were a weird, failed experiment," Nicholas Longrich, study co-author and a professor at the University of Bath, said according to National Geographic. "Now we're finding that they pulled off a major evolutionary explosion, doing everything from acting as top predators to feeding on tiny plankton."

The expeditions were funded by the Agouron Institute, Carlsberg Foundation and Geocenter Denmark. The study was published online in the journal Nature.