The Kansas chalk has been the premier locality for North American pterosaurs (flying reptiles), specifically the genus Pteranodon (tur-an-o-don). Many toothed pterosaurs had been found in Europe since the early 1800’s, so when a Yale University scientific expedition to Kansas found wing bones in 1870, it was assumed that these pterosaurs also had teeth. A few years later, a skull was found, showing that it had no teeth. Therefore, Professor Marsh named it Pteranodon, which means “wing without tooth.”
Flying reptiles have an odd flying apparatus. The extremely long phalange bones of their fourth digit provide an extended wing length for flying. They flew with their little finger!
The remaining three fingers are adapted with large claws that could have been used for clinging to surfaces. Pteranondon could flap its wings, but paleontologists assume that it mainly soared over the seassearching for small fish, then diving down and skimming the surface for its catch.
There are two main groups of pterosaurs from the Kansas chalk: Pteranodon and Nyctosaurus (nick-toe-sore-us). Both lack teeth; they are only different in body size and the structure of the upper arm bone (humerus). The heads of Pteranodons are very large in proportion to their bodies and have crests of different sizes and shapes.
The crests were probably used as a guiding rudder in flight. However, some Pteranodons only have small crests and there are theories that ones with large crests were males and ones with small crests were females.
©2015 Keystone Gallery / Photos © Barbara Shelton unless otherwise noted