Two paleontologists uncovered the remains of 130 species of dinosaur and collected thousands of specimens, putting American science on the world stage in the late 1800s, but their professional rivalry left both men alone and almost penniless.

In the summer of 1868, paleontologist Othniel Charles Marsh boarded a Union Pacific train for a sightseeing excursion through the heart of the newly opened American West. While most passengers simply saw magnificent landscapes, Marsh soon realized he was traveling through the greatest dinosaur burial ground of all time. Ruthless, jealous and insanely competitive, Marsh would wrestle over the discovery with the other leading paleontologist of his generation, Edward Drinker Cope. Over time, the two rivals would uncover the remains of dozens of prehistoric animals, including 130 species of dinosaur; collect thousands of specimens; provide ample evidence to prove Charles Darwin’s hotly disputed theory of evolution; and put American science on the world stage. But their professional rivalry eventually spiraled out of control. What began with denigrating comments in scientific publications led to espionage, the destruction of fossils and political maneuvering that ultimately left both men alone and almost penniless.