(Cheryl of the Clue Crew walks with a robotic Stegosaurus.)  You might encounter a real Stegosaurus if you can go back to the late part of this geological period, a good one for dinosaurs
Save ... Guanlong wucaii, Late Jurassic (160 Ma), Discovered by Xu et al, 2006 
..... lived about 103 million years ago during the late Early Cretaceous period.