Factual error: The trip goes back 65 million years. This is the late Cretaceous period. The Allosaurus was a Jurassic period dinosaur, which became extinct before the beginning of the Cretaceous period. Granted, the Allosaurus was probably the most powerful predator of its time, the events in this movie take place long after the time of the Allosaurus.
Factual error: In the courthouse scene the flag behind the judge is a Texas state flag, not a Georgia state flag.