You might have seen Dilophosaurus in the first Jurassic Park Motion Picture. Please be sure not to follow the movie on a factual basis. The movie was more for entertainment that a study. In the movie it shows Dilophosaurus spitting an acid venomous tar like substance and showing a neck frill. There is absolutely no evidence that Dilophosaurus could do this and no fossil records of a neck frill. There were no poison glands intact and space for poison glades anywhere in fossil discoveries as well. In the film they claimed that they were only 3 feet tall and 5 feet in length, but they were much bigger. From the many findings of complete fossils the Dilophosaurus was much bigger. It was 21 feet long and up to 7 feet in height. Typically the weight of an animal of these dimensions was about 1/2 ton (1000lbs). This species was first discovered in 1942 by a man by the name of Sam Welles and all finding have been in Arizona. It was described in 1954, but had not been given its name until 10 years later. The name Dilophosaurus actually means "two-crested-lizard". It was from the ceratosaur group, but through recent studies it has crossed the line between being in the groups of both ceratosaurian and tetanuran theropods. In future discoveries it's sure that scientists will be watching for which group the Dilophosaurus should actually be in.
The Dilophosaurus was an aggressive carnivore and was one of the biggest for the region it was found (Tuba city, Arizona, USA ). It is determined that Dilophosaurus probably hunted and lived in herds because there were discoveries with up to three complete skeletons found together. This dinosaur had many interesting features such as short hind legs, four toed feet, short forelimbs, three fingered hands, and an opposable thumb for each hand. The claws of the Dilophosaurus were very thick for the size of the prehistoric predator. They were probably its main offense along with its size. The strong hind legs showed that it could probably run like a horse. Out in the open its estimated top speed was 26(mph). As for its mouth, it had a loose weak jaw so this probably was not the animals' main offensive weapon for hunting.
One of the most unique features of the Dilophosaurus was the two large crests upon its head. The rounded pair of semicircular bony crests were on its head faced vertically and the structure of them was fragile in certain areas. In these area's they were reinforced with struts on strong bone. There has not been confirmed evidence for these crests, but other various species of dinosaur did have them also. Crests were also found on fossils of the Parasaurolophus and Corythosaurus, however these were herbivores and the crests were very different. The Dilophosaurus crest was solid unlike the other dinosaurs with crests, which were hollow and had chambers connected for vocal reasons. It's noted that the Dilophosaurus crest was probably for a list of possibilities. It could be true that the crest was for breeding purposes. It's very common of animals today that have strange features to attract of opposite sex such at changing color, etc. Also another common thought is that these crested could've been for temperature controlling. It is unsure if dinosaurs were warm or cold blooded, but if Dilophosaurus was cold blooded then these crests would've been a perfect function for cooling its body temperature. This is a highly believed by most scientists because the region of Arizona in the Jurassic Era was defiantly a desert region being very hot with minimal water around.
Just for fun we have a soundclip available for you to hear what a Dilophosaurus could've sounded like. Click to the Dinosaur Sounds area to hear it. Please note that the dinosaur sounds are only for entertainment and are not an actual fact