 Knight's foray into paleoart can be traced to a commission ordered by Dr. Jacob Wortman in 1894 of a painting of a prehistoric pig, "Elotherium", to accompany its fossil display at the American Museum of Natural History.Knight, who had always preferred to draw animals from life, applied his knowledge of modern pig anatomy to the painting, which so thrilled Wortman that the museum then commissioned Knight to paint a series of watercolors of various fossils on display.Throughout the 1920s, '30s and '40s, Knight went on produce drawings, paintings and murals of dinosaurs, early man, and extinct mammals for the American Museum of Natural History, where he was mentored by Henry Fairfield Osborn, and Chicago's Field Museum, as well as for "National Geographic" and many other major magazines of the time, culminating in his last major mural for the Everhart Museum of Scranton, Pennsylvania, in 1951.