 The Jurassic Park movies were fantastic, but they did get a few things wrong. Velociraptors, for instance, were smaller than what was depicted. No-one knows if T-Rex could only detect your movement. And the crested predator Dilophosaurus was nothing like the small venom spitting and neck frill expanding creature depicted in the movie. Ironically, it was one of the few dinosaurs in the movie that actually lived in the Jurassic period! Dilophosaurus was one of the earliest large predatory dinosaurs, a medium-sized theropod (a three-toed carnivore with claws). Slender and lightly built, its size was comparable to that of a grizzly bear. The largest known specimen weighed about 400 kilograms, measured about 7 metres in length, and had a skull was 59 cm long.  All of the non-avian dinosaurs were confined to a geologic era called the Mesozoic. This was divided into three periods: the Triassic, the Jurassic and the Cretaceous. The latter ended with a mass extinction 66 million years ago. Birds were the only dinosaurs who survived the catastrophe. 
Dilophosaurus lived during the early Jurassic period, about 190 million years ago. It was a fast-moving carnivore that roamed what's now Southwestern North America. A kink in its upper jaw suggests that it might have eaten a certain food, or attacked by gripping and holding on to prey – modern crocodiles have a similar kink. The pair of thin bony crests on its head may have been for display. Dilophosaurus was the biggest known North American land animal alive at the time, and an indicator of the much bigger carnivores to come. Due to the limited range of movement and shortness of its front legs, the mouth may instead have made first contact with its prey. The function of the crests on its head is unknown; they were too weak for battle, but may have been used as a visual display, such as recognition and mate selection. |