Barnum Brown was named after P.T. Barnum, but his passion was more mundane than the showman's. As a young boy, he followed the machinery of his father's Kansas strip mine operation to search for fossils. Brown studied paleontology in college (a fairly new discipline at the time) and made a reputation for himself. Under the patronage of Henry Osborn of the American Museum of Natural History, Brown was able to find amazing dinosaur fossils and get his master's degree.
An expedition to Montana in the summer of 1902 yielded Brown's biggest discovery yet- a new species of dinosaur that may have been 40 feet long, which Osborn named Tyrannosaurus rex. Osborn also allowed others to credit him with the discovery. Brown remained in the background, and even found two more T. rexes while Osborn was publicizing the find. But the dinosaur itself was an even bigger star than either man. Read the story of the man behind T. rex at Mental Floss.
(Image credit: Jon Parise)