Within both sets of eggs, researchers had discovered fossilized embryos. The question remained: could Erickson use a dentin analysis to learn about the ages of these dinosaurs?
Could this teach us about the time it took them to hatch? Leading a team of researchers, Erickson got to work on finding out the answer.
At about seven ounces and close to the shape of a potato, the eggs were relatively small and didn't give Erickson a lot to work with. However, a few other specimens gave him plenty of work to do.
These dino egg fossils had been discovered in the Canadian province of Alberta and belonged to the species of dinosaur known as the Hypacrosaurus Stebingeri, which is sort of like a cross between a T-Rex and a duckbill dinosaur. It was a bipedal herbivore and usually grew to about nine meters in length.
The duck-billed Hypacrosaurus laid eggs that weighed almost nine pounds. They have the same proportions as a volleyball.
While they were much bigger and had specimens entirely different from those Erickson had started his study on, he found plenty of exciting material.
They had a couple of steps to work through. First, Erickson and his team used a computed tomography scan, or a CT scan, to inspect the dentition that had developed in all of the embryos' jaws.
Carefully – very carefully – they removed a number of teeth that had already formed from the fossilized eggs. Under microscopes, they could zoom into the finest details of the specimens that had lasted millions of years to see the information they had been looking for.
In fact, according to Erickson, the lines of dentin on each tooth easily became clear and visible. When he was speaking with the Washington Post, he said: “I knew we were in business.”
Erickson had determined it was possible for the team to determine how long the embryos had been alive. In an FSU statement, Erickson explained: “We could literally count [the dentin] to see how long each dinosaur had been developing.”