or 30 years, Ostrom steadily and meticulously refuted critics of his theories. He is shown here in the Yale Peabody Museum, near a Deinonychus in mid-leap.
Deinonychus in full sprint, as drawn by Robert Bakker ’67—a student of Ostrom’s and a crusader for the view that dinosaurs were active, dynamic animals. The drawing appeared in Ostrom’s 1969 paper announcing the discovery of Deinonychus.
John Ostrom was born February 18th, 1928. He was the paleontologist that changed the way we look at dinosaurs. Before him, they were slow, dump, plodding animals that couldn't help but go extinct. Many researchers in his day thought them scientifically boring. Wow, how far they had fallen from the early 20th century. While digging up Deinonychus in 1964, it struck him that if he didn't know he was digging up a dinosaur, he'd have sworn he was digging up a giant bird. And thus, the dinosaur renaissance was born. The Yale Alumni has a great feature article from 2014 about John Ostrom.
In the summer of 1970, early in the research that would radically transform how we think about birds, dinosaurs, and the origins of animal flight, Yale paleontologist John H. Ostrom was traveling through Europe studying pterosaur fossils. His itinerary took him, in early September, to the Teylers Museum in Haarlem, the Netherlands. Ostrom, then 42, was an unprepossessing figure and the world’s leading authority on dinosaurs, and the museum curator was pleased to leave him alone with the twin halves of the limestone slab catalogued TM6928 and 29.
This fossil was a dinner plate–size muddle of limb fragments, vertebrae, and ribs preserved in limestone from the Solnhofen beds. It had been discovered near Riedenburg, Germany, in 1855 and named by the great nineteenth-century paleontologist Hermann von Meyer. Von Meyer later became famous for the first scientific description, in 1861, of Archaeopteryx. Coming just after the publication of Charles Darwin’s On the Origin of Species, the unveiling of that 150-million-year-old urvogel, or archetypal primitive bird, made an international sensation. With Archaeopteryx, it seemed as if the proof of evolutionary theory had arrived, like the Ten Commandments, engraved in stone. But in 1857, the confusing fossil von Meyer was describing—the future TM6928 and 29—seemed like something far more ordinary: another pterosaur, a type of flying reptile. He dubbed it Pterodactylus crassipes.
That didn’t make sense to Ostrom as he puzzled over the ankles, toes, and arm bones of the fossil that day in 1970. He could envision the ways they might fit together just by examining the proportions of the bones and the shape of their articulations. But it wasn’t like any pterosaur he had ever seen. Ostrom had recently finished describing a remarkable dinosaur he had discovered a few years earlier in Montana. His monograph on Deinonychus included exquisitely detailed descriptions showing how the bone endings and attachments helped make these dinosaurs such fast, agile little killers. To Ostrom, the bones of the Teylers specimen looked an awful lot like those of Deinonychus. And there was something more.