The Sinclair Refining Company advertising department began using dinosaurs in 1930s advertisements as a symbol
dramatizing the age and quality of crude oil Sinclair petroleum products were made from.
When the company took part in the technology section of the 'Century of Progress' Chicago World's Fair in 1933 - 1934, a life size replica (over 70 feet long) of Apatosaurus was displayed at the exhibit's entrance.
As a result of the wildly popular display, an 8 year promotional campaign began.
'Dino' the Sinclair Dinosaur appeared on envelopes, letterhead and in postage meter machine indicia from 1934-1942.
The first Sinclair 'Dino' advertising design incorporated a small dinosaur image.
Although the company's advertising department initially opted for the larger dinosaur image for appearances sake, the smaller dinosaur design was not abandoned and came into business use 11 months after the larger design.