
John Ostrom, in the field
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.

Half of the Teylers specimen
Ostrom picked up one of the slabs, carried it over to the window, and held it up at an angle in the light. First one way, then the other. The late afternoon sun caught on some faint ridges. Ostrom was seeing, unmistakably, the clear impression of feathers. This fossil wasn’t Pterodactylus after all. It was another Archaeopteryx. In fact, it would have been the scientific world’s first Archaeopteryx, if von Meyer had gotten his taxonomy right.
In 1970, only three other specimens of Archaeopteryx were known to exist. But this was by no means the only thing that excited Ostrom at that moment. His mind was already ticking over about the resemblance to Deinonychus—and the unsettling idea that the wrist and shoulder bones of a primitive bird should be identical to those of a small meat-eating dinosaur.
To write a proper technical description, Ostrom needed to take the specimen home to the Peabody Museum at Yale for closer study. A crisis of conscience ensued: should he mislead the Teylers curator, telling him it was merely a pterosaur, only to make the great discovery back home? Or should he come out with the truth and risk that the museum would lock up these suddenly precious slabs of rock? Being a “squeaking honest” man, in the words of a former student, Ostrom confessed his belief that it was Archaeopteryx.
The curator immediately took back TM6928 and 29 and hurried out of the room. Ostrom slumped in his seat, despairing. A few minutes later, the curator returned Read the rest of this entry »
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