Dimorphodon (Greek for "two-formed tooth"); pronounced die-MORE-foe-don
Shores of Europe and Central America
Middle-late Jurassic (175-160 million years ago)
Size and Weight:
Wingspan of four feet and a few pounds
Unknown; possibly insects rather than fish
Large head; long tail; two different types of teeth in jaws
Dimorphodon is one of those animals that looks like it was assembled wrong out of the box: its head was much bigger than that of other pterosaurs, even near-contemporaries like Pterodactylus, and seems to have been borrowed from a larger, terrestrial theropod dinosaur and planted on the end of its small, slender body. Of equal interest to paleontologists, this middle- to late Jurassic pterosaur had two types of teeth in its beaked jaws, longer ones in front (presumably intended for snagging its prey) and shorter, flatter ones in back (presumably for grinding this prey up into an easily swallowed mush)-hence its name, Greek for "two shapes of tooth."
Discovered relatively early in paleontological history-in early 19th century England by the amateur fossil-hunter Mary Anning-Dimorphodon has occasioned its share of controversy, since scientists didn't have a framework of evolution within which to understand it. For example, the famous (and notoriously cranky) English naturalist Richard Owen insisted that Dimorphodon was a terrestrial four-footed reptile, while his rival Harry Seeley was a bit closer to the mark, speculating that Dimorphodon might have run on two legs. It took years for scientists to realize that they were dealing with a winged reptile.
Ironically, according to the latest research, it may be the case that Owen was right after all. The big-headed Dimorphodon simply doesn't appear to have been built for sustained flight; at most, it may have been capable of fluttering clumsily from tree to tree, or briefly flapping its wings to escape larger predators. This may have been an early case of secondary flightlessness, since a pterosaur that lived tens of millions of years before Dimorphodon, Preondactylus, was an accomplished flyer. Almost certainly, to judge by its anatomy, Dimorphodon was more accomplished at climbing trees than gliding through the air, which would make it the Jurassic equivalent of the contemporary flying squirrel. For this reason, many experts now believe that Dimorphodon subsisted on terrestrial insects, rather than being a pelagic (ocean-flying) hunter of small fish.