'Swimming Head' Was King Of The Sea 500 Million Years Ago: Study

The orca is apparently the king of the ocean  these days, but in prehistoric times, that title went to a “swimming head.”

That’s according to paleontologists at Canada’s Royal Ontario Museum who recently discovered a gigantic relative of the horseshoe crab in the 500-million-year-old Burgess Shale in British Columbia, according to CBS News .

The newly discovered species is known as “Titanokorys gainesi” and measured 19.7 inches at a time when most ocean-dwelling organisms were barely the size of a pinky finger.

“The sheer size of this animal is absolutely mind-boggling, this is one of the biggest animals from the Cambrian period ever found,” Jean-Bernard Caron, the museum’s Richard M. Ivey curator of invertebrate paleontology and an associate professor at the University of Toronto, said in a press release  touting the discovery.

According to the release, Titanokorys belongs to a group of primitive arthropods called radiodonts, which “had multifaceted eyes, a pineapple slice-shaped, tooth-lined mouth, a pair of spiny claws below its head to capture prey and a body with a series of flaps for swimming.”

The creature’s head is “so long relative to the body that these animals are really little more than swimming heads,” Joe Moysiuk, a Ph.D. student in ecology and evolutionary biology at the University of Toronto who co-authored the study, said in the release.

Researchers are still trying to figure why the creature’s head was so big, but speculate it was an adaptation to help it live near the seafloor, according to CNN .

“Their limbs at the front looked like multiple stacked rakes and would have been very efficient at bringing anything they captured in their tiny spines towards the mouth. The huge dorsal carapace might have functioned like a plough,” study co-author Jean-Bernard Caron told CNN .

The fossils will be on display at the Royal Ontario Museum starting in December.