No... no dinosaurs. You guys are getting distracted here. Fuck the dinosaurs. Fish were laying eggs too back then, but you didn't see any chickens crawl out of the ocean and sprout claws did you? No.
Plus, the dinosaurs were wiped out by over hunting and poachers long before the chicken evolved from small forest dwelling rat-like creatures into the majestic, proud symbol of American freedom that it is today.
[Example: Small rat-like forest creature]
[Example: Proud American Status Symbol]
