Paleontologists find massive half-billion-year-old fossil species in Canadian Rockies

Sept. 8 (UPI) -- Paleontologists have discovered a massive new arthropod fossil species that lived in North America during the Cambrian period more than a half-billion years ago.

The fossil remains were uncovered from the Burgess Shale deposit found throughout Canada's Kootenay National Park.

Scientists described the new species, Titanokorys gainesi, in a paper published Wednesday in the journal Royal Society Open Science.

Though the horseshoe crab-like arthropod measured just over a foot-and-a-half in length -- a moderate size by today's standards -- it would have dwarfed the mostly tiny species that occupied the seas of the Cambrian period.

"The sheer size of this animal is absolutely mind-boggling, this is one of the biggest animals from the Cambrian period ever found," lead study author Jean-Bernard Caron, curator of invertebrate palaeontology at the Royal Ontario Museum, said in a press release.

Titanokorys gainesi was a member of a primitive group of arthropods called radiodonts.

The pineapple-shaped creature sported a smooth exoskeleton, multifaceted eyes and a tooth-lined mouth. It used a pair of rake-like claws positioned directly below its mouth to scoop up prey from the seafloor.

"Titanokorys is part of a subgroup of radiodonts, called hurdiids, characterized by an incredibly long head covered by a three-part carapace that took on myriad shapes," study co-author Joe Moysiuk said in a press release.

"The head is so long relative to the body that these animals are really little more than swimming heads," said Moysiuk, a doctoral student in ecology and evolutionary biology at the University of Toronto.

Scientists aren't sure why radiodonts evolved such a diversity of head shapes and sizes, or what allowed Titanokorys to reach such tremendous sizes, but the group's evolutionary success suggests they were well adapted to life on or near the Cambrian seafloor.

"These enigmatic animals certainly had a big impact on Cambrian seafloor ecosystems," said Caron, who is also an associate professor of ecology and evolutionary biology at the University of Toronto.

"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," Caron said.

The Burgess Shale found throughout the Canadian Rockies has yielded a variety of Cambrian arthropods through the years.

Just a few years ago, scientists uncovered a sizable radiodont species with a body shaped like Han Solo's beloved spaceship, the Millennium Falcon. They named the species Cambroraster falcatus.

Authors of the latest study estimate Titanokorys and Cambroraster competed for the same resources.