Pterosaurs: No Thanks, I'll Walk

It is the dream of children of any age to fly, and I don’t mean United or Delta. Yet if new research is right, then at least some of the magnificent flying reptiles of the Mesozoic called pterosaurs preferred to walk, thank you very much—at least for mealtime.

Pterosaurs called azhdarchids lived during the Upper Cretaceous (roughly 145 million to 65 million years ago), and include such crowd favorites as the gigantic Quetzalcoatlus northropi, with a wing span of 35 feet. Paleontologists studying a fossils have concluded that they were “vulture-like scavengers, sediment probers, swimmers, waders, aerial predators, or stork-like generalists [or, most recently] . . . skim-feeders, trawling their lower jaws through water during flight and seizing aquatic prey from the water’s surface,” write scientists in a paper being posted in the journal PLoS One tonight.

Mark Witton and Darren Naish of the University of Portsmouth beg to differ. That model, they continue, “lacks critical support from anatomy and functional morphology.” For instance, these toothless pterosaurs lacked the compressed lower jaw and shock-absorbing apparatus that you need if you’re going to plow into a lake to score chow.

Instead, an analysis of these pterosaurs’ anatomy (weak jaws, ill-suited for crashing into water and snaring prey; poor neck flexibility, forcing the creatures to hold their necks like crocodiles rather than flex it like seagulls; wings better suited to soaring on rising thermals rather than flapping in precision-controlled flight down to the surface of a lake or sea) as well as their footprints (showing they were good walkers and runners, but with small padded feet better for strutting around on land than for wading around lake margins or swimming should they land on water) and the distribution of their fossils (in terrestrial more than marine sediments) adds up to one conclusion, the scientists say: azhdarchids (from the Uzbek word for “dragon”) used their long limbs to stalk, picking up small animals and other prey from the ground.

“All the details of their anatomy, and the environment their fossils are found in, show that they made their living by walking around, reaching down to grab and pick up animals and other prey,” said Naish. Their “bizarrely stiff neck has previously been a problem for other ideas about azhdarchid lifestyle, but it fits with our model, as all a terrestrial stalker needs to do its raise and lower its bill tip to the ground.”

Based on the fossils, Witton has produced images of the 10-foot-tall azhdarchid named Hatzegopteryxwould standing beside a man, a group of Quetzalcoatlus strolling around a prairie picking off baby dinosaurs for lunch, and one of them flying toward you.

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