How to tell if a T. rex is expecting
Chemical test of fossil detects a kind of estrogen-fueled bone that’s also found in egg-producing female birds
![T. rex and bone](https://i0.wp.com/www.sciencenews.org/wp-content/uploads/2016/03/031716_mr_trex-brief_free.jpg?fit=861%2C460&ssl=1)
IT’S A GIRL New chemical analyses can reveal whether a T. rex was “pregnant,” and thus female, by detecting the presence of loosely woven “medullary bone” (light colored material in inset picture) inside a fossilized bone.
Sofia Santos/Shutterstock, inset: M. Schweitzer et al/Scientific Reports 2016