U of A student involved in first discovery of baby tyrannosaur fossils

Baby tyrannosaur fossils discovered U of A PhD student Mark Powers was involved in the discovery of some tiny fossils that hold some big clues about the tyrannosaurus.

EDMONTON — A PhD student from the University of Alberta has helped unearth the first ever baby tyrannosaur fossils.

The U of A says the fossil discovery will help shed new light on how dinosaurs grow.

“The discovery of embryonic material is a huge find in our efforts to understand how some of the most popular and charismatic dinosaurs began their life, and grew to immense sizes,” Mike Powers, the second author on the study and PhD student, said.

The study was led by U of A graduate Greg Funston and focused on two fossils of interest: a small toe claw of an Albertosaurus sarcophagus found near Morrin, Alta., and a small lower jawbone of a Daspletosaurus homeri in Montana.

According to the release, the claw is roughly 71.5 million years old and the jawbone is about 75 million years old.

“Tyrannosaurs are represented by dozens of skeletons and thousands of isolated bones or partial skeletons,” Powers said.

“But despite this wealth of data for tyrannosaur biology, the smallest identifiable individuals are aged three to four years old, much larger than when they would have hatched. No tyrannosaur eggs or embryos have been found even after 150 years of searching—until now,” he added.

The extraordinary discovery will help further assist researchers with their study, according to the release.

“There were two surprising results. The first is that the small tyrannosaur teeth were distinct from the teeth of older individuals—having not yet developed true serrations along the cutting edge of its teeth, as is iconic of the juveniles all the way through to adults,” Powers said.

“The second was the estimated size of the embryos. The specimen belonging to the toe claw was estimated to be about 110 centimetres long, while that of the jaw bone was about 71 centimetres.”

The size estimates are said to match well with the hypothetical hatchling proposed by the late American-Canadian paleontologist Dale Russell back in 1970, according to Powers.

Powers noted, “This was an unexpected but surreal result, as the study was published in a special issue of the Canadian Journal of Earth Sciences honouring Dale Russell for his contributions to the field of paleontology.”