Pterosaurs weren't birds. They weren't dinosaurs, either. And they are definitely more than just pterodactyls. As an order, the pterosaurs contained a huge amount of diversity. Sordes pilosus looked like a flying monkeyduck. Quetzalcoatlus northropi was an extra in The Dark Crystal. Thalassodromeus sethi looked like something your brain would invent after watching Froot Loops commercials on acid.
But, despite that wide variety (and, from what scientists can tell, their ubiquity on every continent), it's incredibly rare to find pterosaur fossils. In fact, all the freaky pterosaurs we can recreate in pictures probably only represent a fragment of the order's true diversity. There are many more pterosaurs whose fossil remains aren't well-preserved or numerous enough for us to get a good idea of what they looked like. Why? This video from the American Museum of Natural History explains it.
This pterosaur lived about 155 million years ago near a lake in what is now southern Kazakhstan where it likely dined on fish and other small prey. Its broad wings stretched from its wing bones to its ankles, and another flap of skin connected its legs, which it may have pumped during flight. Some fossils show that Sordes pilosus kept warm with a thick coat of fibers similar to fur.
This large pterosaur species lived around 70 million years ago on a plain in what is now western Texas. With a wingspan of at least 33 feet , Quetzalcoatlus northropi was about as big as a two-seater plane—larger than any other known flying animal. Quetzalcoalus northropi was named after Quetzalcoatl, a Mexican god of the air.
Thalassodromeus sethi had a crest three times larger than the entire rest of its skull, when seen from the side. Indeed, it had the largest crest of any known vertebrate. This large pterosaur species, with a wingspan of 14 feet, lived around 110 million years ago near a lagoon in what is now Brazil.
All images and captions courtesy the American Museum of Natural History.