The Lost World is a 1925 silent film adaptation of Arthur Conan Doyle's 1912 book of the same name. The movie stars Wallace Beery as Professor Challenger. This version was directed by Harry O. Hoyt and featured pioneering stop motion special effects by Willis O'Brien (an invaluable warm up for his work on the original King Kong directed by Merian C. Cooper and Ernest B. Schoedsack). Writer Doyle appears in a frontispiece to the film.

The journal of explorer Maple White is recovered from a plateau in Venezuela featuring sketches of dinosaurs, which is enough proof for the eccentric Professor Challenger that dinosaurs still walk the earth. With that, John Roxton (sportsman), news reporter Edward Malone (who wishes to go on the expedition to impress his fiancée,) Challenger and Paula White as well as an Indian servant, Zambo, and Challenger's butler Austin leave for the plateau where they indeed find the prehistoric creatures and experience ever more frightening adventures.

CAST
Sir Arthur Conan Doyle – Himself (appears in a frontispiece to the film)
Bessie Love – Paula White
Lewis Stone – Sir John Roxton
Lloyd Hughes – Edward Malone
Wallace Beery – Professor Challenger
Arthur Hoyt – Professor Summerlee
Alma Bennett – Gladys Hungerford
Virginia Browne Faire – Marquette the half-caste girl (uncredited)
Bull Montana – Ape Man/Gomez
Francis Finch-Smiles (billed as "Finch Smiles") – Austin
Jules Cowes (in blackface) – Zambo
Margerette McWade – Mrs. Challenger
George Bunny – Colin McArdle
Charles Wellesly – Major Hibbard (uncredited)
Nelson MacDowell – Attorney (uncredited)
Chris-Pin Martin – Bearer/Cannibal (Scenes Deleted)
Jocko the Monkey – Himself
Mary the Chimpanzee – Herself (uncredited)
Note: All human cast members who are listed in the on-screen credits are billed as "Mr..." or "Miss...."