August 22, 2005 by

John H. Ostrom


Categories: Education, Scientists, Writers/Editors

John Harold Ostrom, a paleontologist who championed the theory that birds descended from theropod dinosaurs, died on July 16 of complications from Alzheimer’s disease. He was 77.
Born in New York City and raised in Schenectady, N.Y., Ostrom originally planned to become a doctor, like his father. While doing undergraduate work at Union College, however, he took an elective course in geology that changed his life. Lectures on dinosaurs and books discussing evolution soon inspired him to become a paleontologist instead.
After earning a doctorate in geology and paleontology at Columbia University in 1960, Ostrom joined the faculty at Yale. He remained there for the next three decades and sparked a renaissance in the study of dinosaurs. Upon his retirement in 1992, Ostrom was named an emeritus professor of geology and geophysics.
Whenever he wasn’t teaching in the classroom, Ostrom led fossil-hunting expeditions in the American West. In 1964, he and his assistant Grant E. Meyer were trekking through central Montana when they stumbled upon the sight of three large claws sticking out of an eroded mound of dirt. With barely contained excitement, the pair uncovered the fossilized remains of a small dinosaur.
Ostrom examined the bones of the two-legged creature and hypothesized they belonged to a predatory animal that lived 125 million years ago. A carnivorous dinosaur, it killed its prey by leaping at it and slashing with sharp, sickle-shaped claws. Ostrom named the raptor Deinonychus (meaning “terrible claw”), and declared that it was once a warm-blooded animal with a high metabolism rate. Once Ostrom published his theories in 1969, fierce debate erupted among paleontologists, many of whom dismissed him as a maverick.
A year later, Ostrom made his second significant contribution in the field of paleontology. While visiting a museum in the Netherlands, he noticed the anatomical similarities between a pterosaur, a gliding reptile, and the Archaeopteryx, a creature that was generally accepted as the earliest known bird. This realization prompted Ostrom to reintroduce the idea that birds had an ancestral link to dinosaurs.
When he presented his theory in 1973, the information caused an uproar among both paleontologists and ornithologists. Despite the fact that Ostrom showed more than 200 anatomical features that birds shared with meat-eating dinosaurs — including a wishbone, swiveling wrists and three forward-pointing toes — many in the scientific community continued to believe that dinosaurs evolved into reptiles, not warm-blooded flying mammals.
The opposition eventually accepted Ostrom’s ideas when a number of small, apparently feathered dinosaurs were found in fossil beds in China. The general public was a bit more accepting of his theory after it was loosely presented in the 1990 book “Jurassic Park” by Michael Crichton, and its 1993 film adaptation directed by Steven Spielberg.
“If there are any people left who don’t believe birds came from dinosaurs, I’d put them in the same group as the flat-earth society,” said John R. Horner, curator of paleontology at the Museum of the Rockies.
Ostrom was the longtime editor of The American Journal of Science, a fellow of the American Academy of Arts and Sciences and the emeritus curator of vertebrate paleontology at the Peabody Museum of Natural History. He published the books “The Strange World of Dinosaurs,” “A Study of Dinosaur Evolution,” and “Marsh’s Dinosaurs: The Collections From Como Bluff,” among others. The Cretaceous period bird/dinosaur Rahonavis ostromi was named in his honor.

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