Author	Title	Publisher	C	Notes
O'Harra, Cleophas C.	The White River Badlands Reprinted in 1976) Bibliographied in: Discovering Fossils: How to Find and Identify Remains of the Prehistoric Past, Frank A. Garcia and Donald S. Miller, Stackpole Books, 1998	South DAkota School of Mines	1920
Ostrom, John H. and John McIntosh	Marsh's Dinosaurs: The Collections From Como Bluff Bibliographied in: Reading Between the Bones: The Pioneers of Dinosaur Paleontology, Susan Clinton, Franklin Watts, 1997	Yale University Press	1966
Osborn, Henry Fairfield	Cope: Master Naturalist (Reprinted in 1978) Bibliographied in: Reading Between the Bones: The Pioneers of Dinosaur Paleontology, Susan Clinton, Franklin Watts, 1997	Princeton University Press	1931
Outram, Dorinda	Georges Cuvier: Vocation, Science and Authority in Post-Revolutionary France Bibliographied in: Reading Between the Bones: The Pioneers of Dinosaur Paleontology, Susan Clinton, Franklin Watts, 1997	Manchester University Press	1984