Currently paleontologists know of four species of giant pterosaur, some of which were as tall as giraffes and had wingspans of more than 30 feet (10 meters).
The huge animals likely relied on updrafts of warm air and wind currents to achieve their record distances, said study co-author Michael Habib, a paleontologist at Chatham University in Pittsburgh.
"They probably only flapped for a few minutes at a time ... and then their muscles had to recover," he said. "In between, they're going to use unpowered flight" and glide.
Even so, the winged reptiles would have needed to burn about 160 pounds (72 kilograms) worth of fat reserves per trip, Habib said.
"They're basically burning off the equivalent of a good-size human on each trip."