A section from the National Amusement Park Historical Association's website:" said:
Olympic Park in 1923 installed the Dip-Lo-Do-Cus, an unusual John Miller designed roller coaster. Its name came from a 84 foot long dinosaur exhibited in the Carnegie Museum in Pittsburgh. His concept was that the coaster would be covered by sheet metal and painted to resemble the tropical region where the dinosaur once lived. The circular cars, had three sections, each holding two passengers. Since the cars, centered upon three points caused an unbalanced condition, as they travelled over the undulated track and banked turns in the figure-8 layout, they revolved giving passengers an exciting ride. It isn’t known whether Olympic Park’s ride was actually covered as the only photos show it looking like a small tight banked open roller coaster. (If anyone knows or has better photos, please contact Jeffrey Stanton.)