The largest creature ever to fly was Quetzalcoatlus northropi, a Cessna-size pterosaur that soared through Cretaceous skies 68 million years ago on wings spanning 30 feet. Fossils of the giant flier were first discovered just 20 years ago in Big Bend National Park in southwest Texas. Ever since the first quetzlcoatluses were unearthed, paleontologists have debated (among other things) what the creatures ate. There was speculation that it was a carrion feeder--eating dead dinosaurs, says Alexander Kellner, a Austrian paleontologist at the American Museum of Natural History. Kellner, though, believes he has found evidence that Quetzalcoatlus was a fish eater and may in some ways have resembled a giant pelican.
Even though the deposits where this animal was found are on the inside of the continent, not near the sea, says Kellner, these were big animals and could certainly fly miles and miles to places where they’d find fish to prey on.
Kellner and University of Texas paleontologist Wann Langston have recently completed an analysis of four skulls from specimens with 15-foot wingspans. (Most paleontologists have assumed that these were juvenile versions of the giant Q. northropi, but Kellner believes that the smaller creatures were a separate species.) Each skull from these smaller specimens--no skull from the larger animals has been found--has a distinctive joint between the upper and lower jaw. The joint is similar to one found in pelicans that enables the birds to swallow fish whole. And on the lower jaw, says Langston, is a bony projection (circled in the photo) that may have been the attachment point for a throat sac.
These features aren’t proof that the small Quetzalcoatlus caught, stored, and ate fish. But Langston feels that is the most likely explanation. Moreover, he says, birds that feed on worms, insects, and other small animals typically have short skulls, where Quetzalcoatlus’s skull is three feet long. It had no teeth; weak, slender jaws; and a long, delicate neck. It doesn’t seem that it could have fed on anything that would have put up resistance, and it is hard to visualize an animal with not much more than a couple of chopstick-like jaws picking at flesh.