A group of Quetzalcoatlus, another type of giant azhdarchid, strolling around a fern prairie eating baby dinosaurs for lunch. (Image: Mark Witton) Ever wondered what a giant azhdarchid would look like flying towards you? Now you know. (Image: Mark Witton)

If you want to understand the feeding habits of the biggest flying animal the Earth has ever known, imagine a stork. Like storks, giant azhdarchid pterosaurs reached down with their beaks to snatch prey – only they probably preferred baby dinosaurs to frogs.


The azhdarchids have puzzled palaeontologists since their fossils became reasonably well known in the 1970s. More than 5 metres in height, they stood taller than a giraffe, and had wingspans of 10 metres or more, dwarfing any known birds. So how did they feed?

Most smaller pterosaurs probably grabbed fish from the sea, like modern gulls or pelicans. Yet azhdarchids had exceptionally large skulls (2 metres), long toothless beaks, and unusually long and inflexible necks, pretty much ruling out aerial fishing as a feeding method.

Another suggestion was that the giant reptiles were soaring scavengers, like modern condors or vultures. Others suggested Quetzalcoatlus, the best preserved big azhdarchid, probed mud looking for shellfish or skimmed the water to catch fish at the surface, like a modern skimmer.

Stiff-necked stalker

Taking a fresh look at the fossil evidence, Mark Witton and Darren Naish of the University of Portsmouth, UK, found azhdarchids lacked all 30 specialised adaptations for skimming seen in the head and neck of the modern avian skimmer, Rynchops.

Similarly, they report that the azhdarchid neck was too rigid to dip their heads into the water on the wing like gulls and terns do.

However, the long stiff neck and huge skull and beak would work well for stalking prey on the ground or in shallow water, the researchers say.

“All a terrestrial stalker needs to do is raise and lower its bill tip to the ground” to seize prey, says Naish. Although most people think of storks as waders, the marabou storks that are most like azhdarchids are terrestrial stalkers that forage in grasslands and other inland habitats, he told New Scientist.

Fox-sized snacks

The giant pterosaurs may have waded at times, but their small padded feet were better adapted to land, and most fossils come from inland areas. Their huge beaks and towering height would have given them plenty to eat on land.

“If your skull is over two meters in length, then bite-size includes everything up to a [baby] dinosaur the size of a fox,” says Witton.

That may have helped them survive and become a common part of inland fauna during the last 10 million years of the Cretaceous period, before they died along with the dinosaurs.

“I think they have got it just right,” says Kevin Padian of the University of California at Berkeley in the US. “Terrestrial foraging and some wading seems to be the right way to go.”

Journal reference: PLoS ONE, DOI: 10.1371/journal.pone.0002271

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