Pterodactyls (by which most people mean either Pterodactylus or Pteranodon) are the world's most familiar pterosaurs, or flying reptiles. Here are 10 facts you may or may not have known about these skin-winged gliders. (See also a gallery of Pterodactylus and Pteranodon pictures.)
1. There's no such creature as a "pterodactyl."
It's unclear at what point "pterodactyl" became a synonym for pterosaurs in general, and for Pterodactylus and Pteranodon in particular, but the fact remains that this is the word most people (and Hollywood screenwriters) use. Working paleontologists never refer to "pterodactyls," instead focusing on individual pterosaur genera (and woe betide any scientist who confuses Pteranodon with Pterodactylus!)
2. Pteranodon was much bigger than Pterodactylus...
The largest species of Pteranodon attained wingspans of up to 30 feet, much larger than any flying birds alive today. By comparison, the earlier Pterodactylus (from the late Jurassic period) was a relative runt, the wingspans of the largest individuals spanning only eight feet or so (and most species boasting wingspans of only two or three feet, well within the current avian range.)
3 ...but it wasn't the biggest genus of pterosaur.
Lately, a lot of the buzz generated by Pteranodon has been co-opted by the truly gigantic Quetzalcoatlus, a late Cretaceous pterosaur with a wingspan of about 40 feet (about the size of a small plane). Fittingly, Quetzalcoatlus was named after Quetzalcoatl, the flying, feathered god of the Aztecs. (By the way, Quetzalcoatlus may itself soon be supplanted in the record books by Hatzegopteryx!)
4. There are dozens of named Pterodactylus and Pteranodon species.
Pterodactylus was discovered way back in 1784, and Pteranodon in the mid-19th century. As so often happens with such early finds, subsequent paleontologists attributed numerous individual species to each of these genera, with the result that the taxonomies of Pterodactylus and Pteranodon are unusually complicated. Some species may be genuine; others may turn out to be nomen dubia.
5. No one knows how Pteranodon used its skull crest.
Besides its size, the most distinctive feature of Pteranodon was its backward-pointing skull crest, the function of which remains a mystery. Some paleontologists speculate that Pteranodon used this crest as a mid-flight rudder, while others insist it was strictly a sexually selected characteristic (that is, male Pteranodons with bigger crests were more attractive to females).
6. Pteranodon and Pterodactylus probably walked on four legs.
One of the major differences between ancient, lizard-skinned pterosaurs and modern, feathered birds is that pterosaurs likely walked on four legs when they were on land, compared to birds' strictly bipedal postures. How do we know this? By the analysis of Pteranodon and Pterodactylus footprints (as well as those of other pterosaurs) preserved alongside ancient dinosaur trackmarks.
7. Male Pteranodons were bigger than females.
As discussed above, in relation to its crest, Pteranodon is believed to have exhibited sexual dimorphism, the males of this genus being significantly bigger than the females (interestingly, in many modern bird species, the females are significantly bigger than the males). Male Pteranodons also had larger, more prominent crests, which may have taken on bright colors during mating season.
8. Pterodactylus was the first pterosaur ever to be discovered.
The "type fossil" of Pterodactylus was discovered in the late 18th century, well before scientists had a firm understanding of pterosaurs, dinosaurs, or (for that matter) the process of evolution. Some early naturalists even mistakenly believed (though not after 1830 or so) that Pterodactylus was a kind of bizarre, ocean-dwelling amphibian that used its wings as flippers!
9. Pteranodon didn't have any teeth.
One of the major differences between Pterodactylus and Pteranodon is that the former pterosaur had a small number of teeth, while the latter was completely toothless. This fact, combined with Pteranodon's vaguely albatross-like build, has led paleontologists to conclude that this pterosaur flew along the seashores of late Cretaceous North America and fed mostly on fish.
10. Neither Pteranodon nor Pterodactylus had feathers.
Despite what many people think, modern birds didn't descend from pterosaurs like Pterodactylus and Pteranodon, but from the small, two-legged theropod dinosaurs of the Jurassic and Cretaceous periods, many of which were covered with feathers. As far as we know, pterosaurs were strictly reptilian in appearance, though it's conceivable that some odd species sported feather-like ornamentation.