What is the meaning of "Thanatotheristes", the name given to a Canadian dinosaur species discovered in the 21st century?

Representing the first new species of Tyrannosaur discovered in Canada in 50 years, Thanatotheristes degrootorum was just identified by a team of researchers with the University of Calgary and the Royal Tyrrell Museum.

This terrifying specimen had been gathering dust in storage inside the Royal Tyrrell Museum in Drumheller when PhD candidate Jared Voris pointed out curiously unique features uncommon in previously studied Tyrannosaur fossils, most notably several prominent vertical ridges running along the upper jaw line.