You may not know his name, but chances are that you have seen his work. Brooklyn-born artist Charles R. Knight (1874–1953) produced paintings and sculptures of dinosaurs, mam­moths and prehistoric humans that adorn the great natural history museums in the U.S. His dinos have appeared as toys, stamps and comics, as well as in books and scientific journals on paleontology. One of Sir Arthur Conan Doyle’s illustrators swiped them for his 1912 novel The Lost World. Some even became movie stars, directly inspiring sequences in the 1933 King Kong and, more indirectly, Walt Disney’s 1940 Fantasia and Steven Spielberg’s 1993 Jurassic Park. Hollywood’s master monster animator Ray Harryhausen, creator of the dinosaurs in the 1966 One Million Years B.C. and other cult classics, based his stop-motion puppets on paint­ings and sculptures by Knight.

Knight is best known for his depictions of long-extinct beasts, but he was first and foremost a wildlife artist—an underappre­ciated aspect of his career. Over the course of his lifetime he created nearly 1,000 portraits of living animals representing 800 species—an astonishingly prodigious output. His prehistoric reconstructions benefited from years of keen observations and detailed anatomical studies of modern-day animals. Painting portraits of living lions, tigers, snow leopards and house cats sharpened his portrayal of a snarling saber-toothed cat defending its kill from a giant, condorlike vulture at the La Brea tar pits. Sketches of zoo elephants prepared him to breathe life into woolly mammoths marching across a snowscape in Ice Age France.

In researching my new book Charles R. Knight: The Artist Who Saw Through Time, I noticed a previously overlooked subtext in Knight’s art and writings. Decades of studying fossil bones with paleontologist Henry Fairfield Osborn, his scientific mentor at the American Museum of Natural History in New York City, impressed Knight with the irrevocability of extinction. He became haunted by the realization that all his beloved animal species were ultimately doomed and that humans were now greatly accelerating the process. During his own lifetime, the once superabundant American bison had been slaughtered to the brink of extermination. In 1901 the U.S. government belatedly adopted the species as an icon by putting Knight’s drawing of a bison bull on a postage stamp and the $10 bill.

Knight came to regard each living species as an irreplaceable treasure. When individuals became very rare, such as the sole surviving passenger pigeon that died in 1914 at the Cincinnati Zoo, he would hasten to sketch them—an artist’s loving homage and farewell. His sympathies did not extend to tyrannosaurs, however. In his 1946 book Life Through the Ages, he wrote that the carnosaurs (a group that includes the tyrannosaurs) “have long since vanished, which perhaps is just as well, because no more sinister beings ever walked the surface of this earth.”

I was stunned to learn that Knight was practically blind for much of his adult life—an ironic twist of fate for an artist whose images were so influential. He painted small, detailed oil sketches on boards a few inches from his eyes, which assistants meticulously enlarged onto the museum walls. Then he would mount the scaffold to add finishing touches. When he looked up at a completed mural, whether of dueling dinosaurs or giant ground sloths and armadillos, it was all a blur. Yet he persevered.

He wished that people could experience, if only in fantasy, the “lost world” he had visited so often in imagination and proposed a theme park filled with life-size dinosaur statues. Unfortunately, it was never created during his lifetime for lack of a sponsor.

Ten years after his death, however, that dream became a reality, thanks to his friend and collaborator Louis Paul Jonas, a gifted taxidermist and animal sculptor. Jonas raised money from Sinclair Oil and modeled nine lifelike fiberglass dino sculptures, including a 70-foot-­long “brontosaur/apatosaur,” for New York’s 1964 World’s Fair. Thousands flocked to enter this prehistoric world, which was like stepping inside a Knight mural—a fitting memorial for the courageous artist who faced darkness and extinction armed only with clay, plaster and paint.

This article was published in print as "Time Traveler."