For a long time, scientists didn't know much about pterosaurs; it was tough to even find fossils of the creatures, since only a tiny fraction died in places where their bones could be preserved. But now, the time is ripe for an exhibition of pterosaurs, says Mark Norell, chair of the American Museum of Natural History's Paleontology Division. "We've learned a lot recently about pterosaurs," he tells mental_floss, "and nobody's ever done an exhibition before."
Norell is one of the curators of the museum's new exhibition, Pterosaurs: Flight in the Age of the Dinosaurs, which opens on Saturday. He prepped by creating a wish list of pterosaur fossils and casts, which he got by exchanging some of the museum's fossil casts and things he'd excavated with museum curators around the world. There were items Norell knew he needed to have for this exhibition: "There's the unique pterosaur embryo. We had to have the eudimorphodon, which is the pterosaur from Italy. We had to have dimorphodon from The National History Museum of London. I really wanted to get Dark Wing," top, a fossil discovered in Germany in 2001 that's so well-preserved scientists were able to see details of the wing structure.
The exhibition doesn't just have fossils; scientists also built full-sized models of different pterosaurs and created interactive programs that allow visitors to fly like the creatures. Here's what we learned from an early tour.
1. Pterosaurs weren’t dinosaurs. In fact, that’s the main myth that Norell wants to dispel. Pterosaurs were cousins of the dinosaurs that evolved from a land-dwelling reptile. They were the first animals after insects to evolve powered flight, and the largest creatures ever to fly.
2. The animals varied widely in size, according to Norell: “They range from Nemicolopterus cryptus, which is about the size of a finch, to Quetzalcoatlus northropi,” above, which had a wingspan of more than 33 feet. So far, more than 150 species of pterosaurs have been discovered, and scientists believe there were probably thousands more.
3. Scientists once imagined many ways that pterosaurs might move on land—including upside down in trees, like sloths, or hopping and running on two feet, like birds—but recently discovered fossil tracks suggest that pterosaurs walked on all fours, folding up their wings like umbrellas.
4. Listen up, producers of Jurassic World: If you're going to put pterosaurs in your movie, make sure they've got a little fuzz. New research has revealed that pterosaurs were actually fluffy, which means they were probably warm-blooded, like bats and birds.
5. Scientists aren’t really sure what pterosaurs used their crests for, but they do have some theories: species recognition, sexual selection, cooling, and steering. But Michael Habib, Assistant Professor of Cell and Neurobiology at the University of Southern California and an expert on pterosaur flight who participated in the exhibition, thinks that last one is unlikely, based on tests scientists have performed on model pterosaur heads in wind tunnels. “In order to get [the crests] into a position where they really help at all—for the few crests that could produce useful force in that regard—you had to put the head and neck into really awkward positions that were potentially damaging to the animal,” Habib says. “That also matches what we see in terms of the anatomy, if that is true. If they were used for some other functions—say, a display function—you'd expect the crest would sometimes be very large, and they would be highly variable in the shape. Sure enough, they’re all over the place. They don't seem to particularly correlate with wing shape and structure at all. And that speaks strongly against any kind of aerodynamic function.” That doesn’t mean the crests wouldn’t have an aerodynamic effect; in fact, they’d increase drag. “They would be costly,” Habib says. “But a lot of display structure is costly.”
6. Their eggs were soft-shelled, and only a few have been found so far. (Dinosaurs, by comparison, laid hard-shelled eggs.) By the time a pterosaur hatched, its wings were fully formed; it probably could have taken off shortly after it hatched. Though scientists once imagined pterosaurs caring for their young in nests, they now believe the young hatchlings were on their own from the start.
7. Pterosaur bones were hollow, with walls as thin as playing cards. Like bird's bones, they were strengthened by internal struts. By comparing pterosaur and bird brain casts, scientists have determined that the creatures' brains were similar in certain ways—both had well developed regions for vision and balance, which are important in flying.
8. Pterosaurs lived from 220 million years ago to 66 million years ago, when they were wiped out with the non-avian dinosaurs.
Photo by Erin McCarthy
9. The first pterosaur discovered and described was Pterodactylus Antiquus (above). It was acquired by a German ruler in the late 1700s and kept in a Wunderkammer, or Curiosity Cabinet; the specimen was eventually named by French naturalist Georges Cuvier, who correctly identified it as a flying reptile, in 1809. (Ptero-dactyle means “wing finger.”) And the discoveries keep coming today: Norell and some colleagues have discovered parts of a new pterosaur that they think is around 15 percent bigger than Quetzalcoatlus.
10. Pterosaurs' closest living relatives are two vastly different animals: Crocodiles and birds.
All photos courtesy of AMNH unless otherwise noted.