Osborn was one of the great dinosaur fossil hunters in the late 19th century. Osborn got a Sc.D. in paleontology from Princeton, and was Professor of Comparative Anatomy there from 1883–1890. In 1891, Osborn was hired by Columbia University as a professor of zoology. At the same time, he got a position at the American Museum of Natural History, New York. He served there as the curator of a newly formed Department of Vertebrate Paleontology.