Dinosaur of the Day - Dilophosaurus

Among the earliest predatory dinosaurs of the Jurassic period, Dilophosaurus was also one the least threatening (unless, of course, you happened to be a small, quivering herbivore). This carnivore was slightly built, much different than the thick, relatively plodding body plans of later theropods like Allosaurus. Presumably, it made up in speed what it lacked in sheer bulk.

As for the distinctive crests over Dilophosaurus' eyes, paleontologists believe these were sexually selected--that is, males with these structures had a better chance of mating with females. Although sexual selection may explain similar features on other dinosaurs, when it comes to Dilophosaurus, this theory is on much better ground--since only some fossils (presumably the males) have been found to have these crests. (By the way, despite what you saw in Jurassic Park, there's absolutely no evidence that Dilophosaurus spit poison at its enemies before zooming in for the kill.)

Illustration: Wikimedia Commons