Pregnant T. rex could aid in dino sex-typing
A pregnant Tyrannosaurus rex that roamed Montana 68 million years ago may be the key to discerning gender differences between theropod, or meat-eating dinosaur, species. Researchers from North Carolina State University and the North Carolina Museum of Natural Sciences have confirmed the presence of medullary bone – a gender-specific reproductive tissue – in a fossilized T. rex femur. Beyond giving paleontologists a definitively female fossil to study, their findings could shed light on the evolution of egg laying in modern birds.