Embryo claw adds insight into `Alberta lizard'
EDMONTON A baby tyrannosaurus fossil found in central Alberta is helping the scientific community get a better understanding of how the dinosaur species developed at an early age.
University of Alberta PHD student Mark Powers was a part of the research team that found a claw from an embryo near the village of Morrin, about 270 kilometres southeast of Edmonton, a few years ago.
The fossil, which dated back roughly 71.5 million years ago, was notable as it captured the dinosaur while still in early development.
The claw, about a centimetre long, was paired with another fossil, a jawbone, which was discovered in the '80s in the United States.
Powers said researchers have a good grasp of tyrannosaurus during its teenage to adult years but there are few records of what they were like while very young.
He said the smallest identifiable tyrannosaur on record is already three to four years old.
“We didn't know anything about them hatching or their first year,” Powers said.
“Finding these two specimens shows that they are around, and it gives us a search image to search for more babies.
“It helps to fill in the entire sequence of growing for a tyrannosaurus. We had a good idea of teenagers and later, but we had no idea about the babies.”
Powers said he spent a lot of time with co-author Greg Funston checking every possible option when considering what species the fossils came from.
The claw was from an Albertosaurus sarcophagus, also known as an Alberta lizard, and the lower jawbone was from a Daspletosaurus horneri, also known as a frightful lizard.
One of the final steps to confirm the fossil's identities came when Powers travelled to Saskatchewan to use a specialized scanner to obtain high-resolution images. He said it was very exciting when they were able to finally confirm the bones did come from tyrannosaurus.
“It honestly blows my mind,” Powers said.
“It's really hard to convey the excitement from the moment because when you're in the moment, it's just mind-blowing. We segmented the jaw and then we blew it up because it is very small. The whole jaw is less than three centimetres.
“When you scan it and blow it up as a 3D model and it looks the size of an adult tyrannosaurus jaw ... to see something be so reliable to the adult for such a small size was quite shocking.”
Powers said as far as he's aware, this is the smallest tyrannosaurus that's been discovered so far.