Prehistoric Life Gallery Children of all ages are struck with a sense of awe as they step past the 35-foot long Tyrannosaurus rex that lowers its head and roars at them! A Triceratops, ankylosaur and a ferocious raptor give a further glimpse into the past. Also represented is the ichthyosaur, a gigantic marine reptile that swam in the waters of Nevada during the time of the dinosaurs.