Mesozoic Mohawks: Why Did Pterosaurs Have Crests? (Video)

Pterosaurs: Flight in the Age of Dinosaurs is now open! Celebrating the extinct flying reptiles in all their odd and amazing glory, the new exhibition spotlights their diversity, too. The 150 species of pterosaurs identified from fossils so far show a tremendous range of sizes, wing-shapes, diet, and much more—including the shapes and sizes of head-crests.

Nyctosaurus lived about 85 million years ago, during the Late Cretaceous. With a wingspan of 6 to 10 feet, the pterosaur also had two long, thin bones sticking out of its head, probably connected by soft tissue, forming a large crest. See this cast fossil in Pterosaurs: Flight in the Age of Dinosaurs.
© AMNH/C. Chesek

The elaborate-ness and size of pterosaurs’ crest peaked in species that lived during the Late Cretaceous period—from about 100 to 66 million years ago, after which pterosaurs became extinct.

Watch a video about pterosaur crests to learn more.

Scientists have many theories about why crests evolved, which include recognizing one's own species, cooling, or even steering through the air. But without living descendants for comparison, and because pterosaur fossils are so rare, it's impossible to say for sure. Another leading theory for why pterosaurs evolved crests is sexual selection—perhaps, as with peacocks’ tails, the larger the crest, the more likely a pterosaur was to attract a mate.

Learn more in the new exhibition Pterosaurs: Flight in the Age of Dinosaurs, open from Saturday, April 5, 2014–Saturday, January 4, 2015.