Plant-eating Thescelosaurus assiniboiensis roamed Saskatchewan 66 million years ago. (Art by Peter Bond)

Researchers say a deer-sized, plant-eating dinosaur that roamed Saskatchewan 66 million years ago is a new species.

The University of Calgary's Caleb M. Brown, his supervisor Anthony P. Russell and co-author Clint Boyd of the University of Texas at Austin have named the dinosaur Thescelosaurus assiniboiensis, with the second part derived from Saskatchewan's historic District of Assiniboia.

The new species is described in the December edition of the Zoological Journal of the Linnean Society.

The dinosaur lived alongside Tyrannosaurus rex and Triceratops, although it was a lot smaller than those two behemoths, the scientists say.

A partial skeleton was found in 1968 in the Frenchman River Valley near Eastend, Sask.

Brown said although similar dinosaurs have been found in Montana, Wyoming, and North and South Dakota, Thescelosaurus assiniboiensis has a number of unique traits that distinguish it from its relatives.

Anyone who wants to see for themselves can find the Thescelosaurus assiniboiensis skeleton at the T. Rex Discovery Centre in Eastend. There's also a replica at the Royal Saskatchewan Museum in Regina.