The researchers found the first fossils of baby tyrannosaurs in Alberta and Montana.
Experts say the fossils are a rare discovery, since little is known about young tyrannosaurs and their development, according to a study published in the Canadian Journal of Earth Sciences on Monday.
The study, led by Greg Funston, was based on two fossils: a small claw found in Morrin, Alta., And a small lower jaw found in Montana.
Tyrannosaurs have been well researched, but fossils of eggs or tyrannosaurus embryos have never been found – until now.
“What this gives us is a starting point that we didn’t have,” said Mark Powers, a doctoral student at the University of Alberta and the study’s second author.
“We had part of the growth spurt and we didn’t really have where they came from. Finding specimens like this, which is definitely a tyrannosaurus in the shell or before it hatches, says something about that development.”
What do the findings mean?
The unpublished findings offer researchers a lot of information.
Using a 3D scan of the fossils and measurements of the bones, the researchers were able to find out more about the size of the young and prove that the specimens are of gestating tyrannosaurs.
The 71.5 million-year-old claw found in Alberta has what Powers called “a cone of cartilage” on the back of the claw, meaning that the area had not yet turned to bone and was still developing.
The approximately 75 million-year-old jaw found in Montana had triangular teeth with shallow roots, confirming that they were the teeth of the first generation of tyrannosaurus.
“This fits with many other embryonic discoveries and studies of birds and other dinosaurs found in the shell, so we suspect it is an embryonic individual compared to an incubated one,” said Powers.
The location of these fossils is also revealing.
The claw was found after a large sediment was removed from an excavation expedition in Alberta several years ago, Powers said.
Generally, remains of smaller dinosaurs are more difficult to find.
Smaller fossils would have been more susceptible to the flowing rivers and floodplains of the Cretaceous period, compared to remnants of larger dinosaurs that are often buried deep and preserved in sediment, Powers said.
The areas where the young dinosaur fossils were found are now possible sites for other important discoveries, according to a professor.
“We don’t have much skeleton at all, these are relatively fragmented pieces. But as we know the area where it looks like tyrannosaurs may have made their nests, we know that we should go back to that place and go over a fine comb and find more and more things”, said Scott Persons, professor of paleontology at the College of Charleston in South Carolina.
“I think without a doubt this is going to happen, so eventually the grand prize of actually finding a tyrannosaurus egg is going to happen.”
