The new species of tyrannosaur were discovered in southern Alberta, Canada, thanks to farmer and palaeontology enthusiast John De Groot, a release from the Royal Tyrrell Museum in Alberta said.
De Groot said that he found the fossils during a hike near Hays, Alberta.
"The jawbone was an absolutely stunning find. We knew it was special because you could clearly see the fossilized teeth," he said.
The new species was given the name of Thanatotheristes degrootorum (its name combines Thanatos, the Greek god of death, with theristes, or "one who reaps or harvests." The second part of the name is in honour of John De Groot).
Palaeontologists say that Tyrannosaurs were a group of large predatory theropod dinosaurs (bipedal meat-eaters) that includes the famous Tyrannosaurus rex.
"Thanatotheristes can be distinguished from all other tyrannosaurs by numerous characteristics of the skull, but the most prominent are vertical ridges that run the length of the upper jaw,” said Jared Voris, a University of Calgary PhD student, and lead author of the study.
Scientists believe that the newly discovered tyrannosaur species lived 79.5 million years ago and could be up to 30 feet long while its weight was about two tons as an adult. According to experts, this is the first new tyrannosaur found in Canada in the past 50 years and one of the oldest tyrannosaur species ever found in North America.
"This discovery is significant because it fills in a gap in our understanding of tyrannosaur evolution," said Dr François Therrien, Curator of Dinosaur Palaeoecology at the Royal Tyrrell Museum.
