The fossils of a 68 million-year-old Tyrannosaurus rex were found in Montana by researchers from the North Carolina State University and the North Carolina Museum of Natural Sciences. The studies indicated medullary bone in the fossils, that could mean the presence of preserved DNA.
The study headed by Mary Higby Schweitzer, Lindsay Zanno and their team indicate that the T. Rex found dates back to the Cretaceous Period and it was indeed pregnant, confirming that the dinosaur was within weeks of giving birth before its death.
Researchers assured that the presence and remainings of medullary bone is only present on living dinosaurs or dinosaurs during egg-laying.
In 2005 lead author Mary Schweitzer, led a group of researchers that found, what it appear to be a bone with blood vessels and medullary bone. But the results were inconclusive
Medullary Bone contains keratan sulfate and in can only be present for a short period of time, once the eggs are laid you can’t find it anymore. During this research the scientists used a different method on the femur sample, to examine the possibilities for keratan sulfate, after running the tests on ostrich and medullary bones the team was able to confirm that the T. Rex had medullary bone tissue.
The results of this study open the window for identifying the sex of dinosaurs, since there hasn’t been a reliable way to distinguish males and female dinosaurs.
“This analysis allows us to determine the gender of this fossil, and gives us a window into the evolution of egg-laying in modern birds” Said Mary Schweitzer, the lead author in a statement, according to the Washington Post.
Source: Washington Post