Othniel Charles Marsh (October 29, 1831 – March 18, 1899) was an American paleontologist.
Marsh was one of the preeminent scientists in the field; the discovery or description of dozens of new species and theories on the origins of birds are among his legacies.
Born into a modest family, Marsh was able to afford higher education thanks to the generosity of his wealthy uncle George Peabody.
After graduating from Yale College in 1860 he traveled the world, studying anatomy, mineralogy and geology.
He obtained a teaching position at Yale upon his return.
From the 1870s to 1890s he competed with rival paleontologist Edward Drinker Cope in a period of frenzied Western American expeditions known as the Bone Wars.