Gertie the Dinosaur (1914)

Gertie the Dinosaur is a 1914 animated short film by American cartoonist and animator Winsor McCay. It is the earliest animated film to feature a dinosaur. McCay first used the film before live audiences as an interactive part of his vaudeville act; the frisky, childlike Gertie did tricks at the command of her master. McCay's employer William Randolph Hearst later curtailed McCay's vaudeville activities, so McCay added a live-action introductory sequence to the film for its theatrical release. McCay abandoned a sequel, Gertie on Tour, after producing about a minute of footage.

More at Wikipedia.