These life-size dinosaur models came to Dinosaur Valley State Park after appearing at the 1964-65 World's Fair in New York. In 1969, after fair sponsor Sinclair Oil merged with Atlantic Richfield and dropped its Dino logo, Glen Rose citizens and Governor Preston Smith persuaded Atlantic Richfield to bring the models to the park. The park acquired the two most impressive of the original nine models featured at the fair, and after touring the country they were installed in time for the park's dedication on October 2, 1970. Sculptor Louis Paul Jonas first created all of the Dinoland exhibit models in clay, then the final versions were cast in fiberglass and polyester resin and assembled in pieces on-site. The Tyrannosaurus rex model had massive jaws that opened and closed, and the 70-foot-tall Apatosaurus originally moved its neck.