Birds evolved from theropod dinosaurs during the Late Jurassic period, however, our knowledge of the initial stages of Avialae's evolution is limited due to a scarcity of Jurassic fossils.
A new study suggests that predatory dinosaurs, such as Tyrannosaurus rex, did not have permanently exposed teeth as depicted in films such as Jurassic Park, but instead had scaly, lizard-like lips covering and sealing their mouths.
A study led by The University of Texas at Austin is providing a glimpse into dinosaur and bird diversity in Patagonia during the Late Cretaceous, just before the non-avian dinosaurs went extinct.