Pterosaurs Took Flight on All Fours

Pterosaurs took flight using all fours, a discovery that flies in the face of previous research on the ancient reptiles, a new study says.

Two of the giant creatures' "legs" were extremely strong wings, which when folded, created "knuckles" that allowed the animals to walk and jump (above left, the pterosaur known as Hatzegotpteryx in an artist's rendering).

The way a bird lifts off—using two legs—doesn't make sense for pterosaurs, which would have had to heave their 500 pounds (227 kilograms) airborne using only their hind legs, the study says.

Instead, the "remarkably strong" animals apparently made a leaping launch in less than a second from flat ground, with no aid from wind or ledges.

"Most people are familiar with images of pterosaurs as very skinny, almost emaciated-looking things—basically a hang glider with teeth," study author Michael B. Habib, of Johns Hopkins University School of Medicine, told National Geographic News. "They're actually built a lot more like Arnold Schwarzenegger than Urkel."

Habib compared bone strength in 20 species of modern birds and 3 species of pterosaurs to develop the new model, announced yesterday by the journal Zitteliana.

The finding is also consistent with the idea that bigger animals require more overall brawn to power their movement, Habib added.

"We put V8 engines in our biggest, heaviest cars, not V4s, like the one in my Camry."