The dinosaurs were made by Delgado in the same fashion as Kong and based on Charles R. Knight's murals in the American Museum of Natural History in New York City. All the armatures were manufactured in the RKO machine shop. Materials used were cotton, foam rubber, latex sheeting, and liquid latex. Football bladders were placed inside some models to simulate breathing. A scale of one-inch-equals-one-foot was employed and models ranged from 18 inches to 3 feet in length. Several of the models were originally built for "Creation" and sometimes two or three models were built of individual species. Prolonged exposure to studio lights wreaked havoc with the latex skin so John Cerasoli carved wooden duplicates of each model to be used as stand-ins for test shoots and lineups. He carved wooden models of Ann, Driscoll, and other human characters. Models of the "Venture", railway cars, and war planes were built.