John Ostrom was born in 1928 and earned a B.A. in biology and geology from Union College in 1951, followed by a Ph.D. in vertebrate paleontology from Columbia University. He joined Yale University's faculty, eventually serving as professor of geology and geophysics and curator of vertebrate paleontology at Yale's Peabody Museum of Natural History.[1]
In 1964, fieldwork in Montana's Bighorn Basin turned up a curved, sickle-like claw belonging to a mid-sized predatory dinosaur Ostrom would name Deinonychus -- "terrible claw." Its skeleton implied an active, agile, upright animal, sharply at odds with the sluggish, tail-dragging image of dinosaurs then standard in textbooks. Ostrom went on to compare Deinonychus directly against Archaeopteryx, and in a landmark 1973 paper argued that birds had evolved directly from small theropod dinosaurs -- a hypothesis initially controversial that is now the scientific consensus.[2][1]
Ostrom's Deinonychus work is widely credited with launching what paleontologists call the "Dinosaur Renaissance" -- a shift, starting in the mid-1960s, from viewing dinosaurs as slow and reptilian to studying them as active, possibly warm-blooded animals worthy of serious biological inquiry. Among his students was Robert Bakker, who carried the argument to a much wider public audience. Ostrom died in 2005 in Litchfield, Connecticut, at age 77.[1][2]