Half a billion years ago, in the Cambrian Period, most animals were smaller than a person's little finger. That makes the recent discovery of a marine predator from that time all the more exciting, as the sucker grew up to one foot (30 cm) long.

The creature has been named Cambroraster falcatus, and its fossilized remains were found in the 506-million-year-old Burgess Shale deposit in Canada's Rocky Mountains. In fact, paleontologists from the Royal Ontario Museum and University of Toronto have unearthed hundreds of Cambroraster fossils over the past few summers, formally describing the animal in a paper that was published this week.

Cambroraster was distantly related to the top marine predator of the time, Anomalocaris. Both animals were members of the extinct Radiodonta group, which was an early offshoot of the arthropod lineage, which includes today's insects and crustaceans. That said, the manner in which Cambroraster fed appears to have been quite unique.

Utilizing spine-covered claws that looked like forward-facing rakes, it likely sifted through sediment on the ocean floor, filtering out small organisms which were then passed up to its circular tooth-lined mouth. Its protective curved upper carapace may have helped it to plough through that sediment, as the carapace of the similar-looking horseshoe crab still does. The second part of Cambroraster falcatus' name is actually a nod to that body section, the shape of which is not unlike that of the Millennium Falcon spaceship from the Star Wars movies.

"The Radiodont fossil record is very sparse; typically, we only find scattered bits and pieces," says Jean-Bernard Caron, Curator of Invertebrate Paleontology at the Royal Ontario Museum. "The large number of parts and unusually complete fossils preserved at the same place are a real coup, as they help us to better understand what these animals looked like and how they lived. We are really excited about this discovery."

Plans call for some of the fossils to be showcased in a new gallery at the Royal Ontario Museum, which is set to open in 2021.

The paper on the research, which was led by University of Toronto grad student Joe Moysiuk, was published in the journal Proceedings of the Royal Society B.

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