Have paleontologists just been winging it? Up to 95 percent of the hip joint reconstructions of pterosaurs and their distant relatives, the most birdlike of dinosaurs, are anatomically impossible, according to new research that used a surprising source. But the study’s conclusions, counters a pterosaur expert, should be grounded.

Fleshing out an extinct animal from bones alone has always been paleontology’s greatest challenge, and mistakes have been made. But a paper published today mak