Sarah and I had a discussion about whether or not the sign would say "Dino Rustler" or something else, and my feeling is that it has to say something else, because Sir Richard Owen hasn't coined the Dinosaur term at this point in history (perhaps when he arrives back in the future he'll get around to it), and no one else could either, because Latin also hasn't been invented yet. Therefore those creatures roaming around can't be Triceratops or Tyrannosaurs, because, y'know, they are just normal animals, they don't get fancy Latin names! At the same time, I would be horrified to describe them as "three horns" and "long necks."
(Three Horns do not play with Long Necks!)