Newly conducted research has suggested that there may have possibly been a new tyrannosaur species that lived in Canada millions of years ago. Approximately 10 million years prior to the Tyrannosaurus rex inhabiting the Canadian province of Alberta, there was another tyrannosaur species called Daspletosaurus that lived there.
Daspletosaurus – meaning “frightful lizard” – lived approximately 77 to 75 million years ago during the late part of the Cretaceous Period. The bipedal dinosaur measured about 30 feet in length (9.1 meters), 9 feet in height at the hips (2.7 meters), and weighed around 3 tons. Its skull measured approximately 3 feet in length (0.9 meters) and contained 72 very sharp and large teeth. It would have eaten several different dinosaur species such as the Hadrosaur and possibly Diceratops and Eoceratops. It was a pretty fast runner with a top speed of around 15 mph (24 kph).
CT scans were conducted by Canadian and Argentinean scientists in order to reconstruct the Daspletosaurus’ brain, inner ear, and surrounding bones (braincase). They performed these scans on two well-preserved skeletons belonging to the species. One of the remains was discovered in 1921 while the other was unearthed in 2001 – both were found in Canada.
After they reconstructed the brains, the researchers realized that they might have come from two different Daspletosaur species. Tetsuto Miyashita, who is a palaeontologist with the Canadian Museum of Nature, explained this further in a press release, “We know that tyrannosaurs had relatively good-sized brains for a dinosaur, and this study shows that this pattern holds for Daspletosaurus,” adding, “Furthermore, based on the shapes of the brain, ear structure, and braincase, we suggest that these two specimens represent distinct species of daspletosaurs.”
They also discovered big bony canals that would have held nerves that moved the dinosaurs’ eyeballs as well as large air sacs that filled the majority of the bones found in the braincase. Ariana Paulina Carabajal, who is a dinosaur braincase expert from Argentina, explained, “These cavities within the bones not only make the huge skull lighter, but also are related to the middle region of the ear.” “The cavities probably helped to amplify sound and assist the system that communicates to the left and right ears, allowing the brain to determine where a sound is coming from.”
This discovery is a perfect example that even though some prehistoric skeletons look identical, they may actually be quite different and possibly an entirely new species; therefore, studying braincases is very important. “Researchers have looked inside so few braincases in dinosaurs, typically one each for whatever species they studied, that this reinforced the assumption that these structures don’t change much within and among species,” Miyashita noted. “We just haven’t looked inside enough skulls to document variation.”
The study was published in the Canadian Journal of Earth Sciences where it can be read in full.