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 evolu