Dilophosaurus?

Question

What were the habits of the Dilophosaurus dinosaur?

Answer 1

Dilophosaurus was a theropod dinosaur from the Early Jurassic Period. The name is (pronounced /daɪˌlɒfəˈsɔrəs/ ("dy-LOH-fo-sawr-us") meaning 'two-crested lizard', because it had two crests (Greek di meaning 'two', lophos meaning 'crest' and sauros meaning 'lizard').

Studies by Rob Gay (2001) show that these crests may have been larger in one sex than in the other. Another curious skull feature was a notch behind the first row of teeth, giving it an almost crocodile-like appearance. This "notch" existed by virtue of a weak connection between the premaxillary and maxillary bones of the skull. This conformation led to the early hypothesis that Dilophosaurus scavenged off dead carcasses, with the front teeth being too weak to bring down and hold large prey. A similar notch is present in most other species of coelophysoid.

"He would have had to kill, if he killed, with his hands and feet, and then pluck the meat from the carcass. He was probably a group animal, in that we found three together. They probably moved around in small herds of family groups, covering a lot of territory because of the ability to travel and to move rapidly."

Even its unusual crests have precedents in Coelophysis. One species that lived in Jurassic Arizona alongside of Dilophosaurus, called Coelophysis kayentakatae (formerly Syntarsus kayentakatae), bore two small, ridged crests above its snout. Dilophosaurus sported a much larger pair of these crests. They might have been used to impress other dilophosaurs, although it has been suggested that they were cooling devices to keep its brain from overheating.

The teeth of Dilophosaurus are much longer and more slender than in most other theropods, and are somewhat unusual in that they sat rather loosely in their sockets. This, combined with its unusually-shaped snout, has caused some speculation about its possible feeding habits. For the first large meat-eating dinosaur, it seems ill-equipped to bite into large prey. Its mouth does seem to be well-adapted to nip and grab, so it might have specialized in snagging small, fast animals. This corresponds nicely to what we know about the diet of its Coelophysis relatives.

Answer 2

Nobody knows, except that they were predators. In Jurassic Park, they were portrayed as having an erectible frill, like the Australian frilled dragon, and spitting venom, like the spitting cobra. These traits are pure speculation, however, since the traits of a frill (without bones) and a salivary poison (not injected by fangs) would be ephemeral and not show up in a fossil.