The Friends of Charles Darwin

Palaeontologists think they have found a way to tell whether dinosaur fossils are from males or females. Writing in Science, a US team describe a specialised type of bone layer in fossils from a T. rex which is similar to one found in female birds. In birds, the special tissue is called medullary bone and is laid down in the limbs of females when they lay eggs. The bone tissue found in the dinosaur fossils most closely resembles the medullary bone of emus and ostriches.