The Valley Of Gwangi

In Mexico at the turn of the 20th century, a cowgirl named T.J. Breckenridge hosts a struggling rodeo. Her former lover, Tuck Kirby, a heroic former stuntman working for Buffalo Bill's Wild West Show, wants to buy her out. Along the way, he is followed by a Mexican boy named Lope, who intends to join the rodeo on a quest for fame and fortune. Tuck meets a British paleontologist named Horace Bromley, who is working in a nearby Mexican desert. Bromley declares the horse to be a prehistoric Eohippus.