Palaeontologists have discovered one of the largest fossils of its era in a Burgess Shale quarry site in Kootenay National Park, in the Canadian Rockies.
Measuring half a metre in length, the fossil – named Titanokorys gainesi – was a giant of the Cambrian ocean some 500 million years ago, when its peers averaged the size of a finger.
Associate Professor Jean-Bernard Caron of the University of Toronto said he couldn’t believe the discovery.
“The sheer size of this animal is absolutely mind-boggling – this is one of the biggest animals from the Cambrian period ever found,” Caron said.
The region has revealed a number of significant discoveries this century, including a smaller, more common species called Cambroraster falcatus.
“The two species might have competed for similar bottom-dwelling prey,” Caron and his colleagues told the University of Toronto.
Joe Moysiuk was a co-author with Caron on their study published in Royal Society Open Science in September, and he described the nature of the Titanokorys gainesi.
“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,” Moysiuk said.
“The head is so long relative to the body that these animals are really little more than swimming heads.”
Kootenay National Park is part of the UNESCO Canadian Rocky Mountain Parks World Heritage Site, noted for the 500-million-year-old history of the Burgess Shale ecosystem.
UNESCO originally tagged the Burgess Shale as “one of the most significant fossil areas in the world”.