The Tyrannosaurus rex may have been the ‘king of the dinosaurs’, but his distant new cousin is no shortage, with the nickname ” Reaper of Death” , the “reaper of death”. It has been discovered by a team of paleontologists from the University of Calgary and the Royal Tyrrell Museum who have published the find of the great Alberta tyrannosaurus in the journal Cretaceous Research. The remains were found near the town of Hays, about 200 kilometers southeast of Calgary.
The new species of dinosaur that has been baptized as Thanatotheristes degrootorum (named after the Greek god of death) was a super predator that was at the top of the food chain . It could measure up to eight meters in length, weigh up to two tons, and would represent the oldest member of the T-Rex family.
A historical moment
The ‘reaper of death’ lived in North America about 80 million years ago and is the first new species of tyrannosaurus discovered in Canada in 50 years and also the oldest of the five species of tyrannosaurus discovered in the country. The other four, Daspletosaurus, Gorgosaurus, Albertosaurus, and Tyrannosaurus , are between 77 and 66 million years old. That’s right: At approximately 79.5 million years old, this species is 2.5 million years older than its closest relative and is directly related to Tyrannosaurus rex .
“Alberta has a rich history of dinosaurs. The discovery of Thanatotheristes Degrootorum is historic , as it marks the first new species of tyrannosaurus to be unearthed in Canada in 50 years. The last tyrannosaurus described from Canada was Daspletosaurus in 1970,” explains François Therrien , Curator of Dinosaur Paleoecology at the Royal Tyrrell Museum.
The identification
The scientists were able to identify the new species by analyzing the unique characteristics of the fossil skull fragments that they estimate would have been nearly a meter long in its adult form. “Thanatotheristes can be distinguished from all other tyrannosaurs by numerous features of the skull, but the most prominent are the vertical ridges that run along the upper jaw ,” said Jared Voris, leader of the work.
Due to the nature of the food chain, these large predators were rare compared to herbivorous dinosaurs. Based on examination of the skull, experts concluded that the ‘reaper of death ‘ had a long, deep snout, similar to the earliest tyrannosaurs that lived in the southern United States. They suggest that the difference in skull shape between the regions could be due to differences in diet and the prey available at the time.
The research also suggests that tyrannosaurs did not share a specific body type, but rather that different species of tyrannosaurs developed particular skull shapes, body sizes, and other physical characteristics, spreading to each of the environments where the species thrived.
“The next step is to further test that hypothesis and compare how tyrannosaurus species differ from various geological regions ,” says Voris.
It’s funny, because what really strikes us about the Thanatotheristes is when they lived. Tyrannosaurs have a family rooted in the Jurassic, more than 150 million years ago, but these carnivores were smaller for most of their history. It wasn’t until the end of the Cretaceous that tyrannosaurs became impressive animals. They are found within the subgroup of tyrannosaurs, and it turns out that Thanatotheristes is one of the oldest, if not the oldest, members of this group.
Regarding the species name, degrootorum honors amateur fossil hunters John and Sandra De Groot for discovering the fossil, and the title Thanatotheristes is a combination of the Greek god of death, Thanatos , and the Greek word for “harvest.”
Referencia: Jared T. Voris et al. A new tyrannosaurine (Theropoda:Tyrannosauridae) from the Campanian Foremost Formation of Alberta, Canada, provides insight into the evolution and biogeography of tyrannosaurids, Cretaceous Research (2020). DOI: 10.1016/j.cretres.2020.104388
