Henry Fairfield Osborn and Jurassic Dinosaur Reconnaissance in the San Juan Basin, Along the Colorado-Utah Border, 1893-1900

Abstract

Henry Fairfield Osborn, vertebrate paleontologist at the American Museum of Natural History, did virtually all of his fieldwork by proxy. Working mostly from his New York office, he detailed a score of fieldworkers to locate and claim fossil localities in advance of collectors from rival museums. This history of a long-forgotten Jurassic dinosaur reconnaissance in the San Juan Basin, which was materially unsuccessful, explores how Osborn found and evaluated potential new field localities. He was relentless in pursuit of fossils, especially in the face of worthy competition. He received his first unsolicited tip about fossils along the Colorado-Utah border in 1893. A collector sent to scout the locality found Jurassic dinosaurs in poor condition and left them behind. Following a second tip about fossils in the same region in 1899—at the height of the second Jurassic dinosaur rush—Osborn sent two more expeditions to search the area. Both of these parties returned empty-handed also. Reliable locality data regarding the presence of typical Jurassic vertebrates would have been very useful to geologists like Whitman Cross, who was then attempting to correlate beds west of the Rockies with better-known strata on the eastern slope. But, in order to maintain a competitive advantage, Osborn kept this locality data to himself.