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.
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.
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.
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.”
Excitement grew around the project as Erickson and his team of researchers got to work.
In the same FSU statement, Erickson's co-author Darla Zelenitsky explained: “Time within the egg is a crucial part of development. But this earliest growth stage is so poorly understood because dinosaur embryos are rare. Embryos might be able to tell us how dinosaurs developed and grew very early on in life and if they are more similar to birds or reptiles in these respects.”