Dinosaurs on the move

Alex Eben Meyer.

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Over fifty years ago, Yale paleontologist John Ostrom published a paper that exploded the long-held notion of dinosaurs as sluggish, tail-dragging lizards. His research on Deinonychus antirrhopus—yes, the dinosaur that later inspired creatures in the movie Jurassic Park—led to a rethinking of dinosaur behavior and biology and, eventually, to scientific acceptance of the idea that birds are descended from dinosaurs.

Now, with Deinonychus as their first case study, Yale researchers have developed a new method for understanding how ancient animals moved. First, they took x-ray videos of guinea fowl walking on a miniature treadmill. “Guinea fowls in particular are skilled at walking on the treadmill,” says Armita Manafzadeh, a postdoctoral fellow with the Yale Institute for Biospheric Studies and lead author of the study.

They used the data to make 3-D models in computer animation software where they precisely measured the birds’ ankle, foot, and toe joints in different poses, assigning each pose a score from 0 to 100 to describe how well the joints fit together. When the team compared the highest-scoring poses when walking or running to the guinea fowl’s typical poses, they found a highly accurate match. (The study was published in Nature Communications.)

“Previously, paleontologists had to rely on examining fossilized bones for information,” Manafzadeh notes. The new technological approach allowed researchers to scan the Deinonychus fossils, to create 3-D models, and, with a great degree of confidence, to reconstruct how Deinonychus would have moved.

Yale’s Peabody Museum is thought to have the world’s best collection of Deinonychus materials, and Deinonychus is important to the evolving understanding of the dinosaur-bird link. But this new methodology will go far beyond one kind of dinosaur. “We will be able to give life to virtually any bones from a museum drawer,” Manafzadeh says, “and future studies will provide more insights into the overall evolutionary history of vertebrate animals—including us.”