Last week on Fossil Friday, as per a reader's request, I presented a fossil from the Mesozoic. I chose a lower jaw from the Jurassic, but mentioning that this fossil was in the movie Jurassic Park made it completely obvious what the fossil was. It was one of the few Jurassic dinosaurs in the movie (apparently the movie should have been called Cretaceous Park).
So what was it?
Dan Phelps was the first to correctly identify it as a Dilophosaurus found in Arizona. Nice job Dan! And since you got it first, I am honor bound to hunt down an invertebrate trace fossil for this Fossil Friday, as per your request.