Observation of Articulated Limb Bones of a Recently Discovered Pteranodon in the Niobrara Cretaceous of Kansas

Abstract

The two genera of flying reptiles from the Niobrara Cretaceous are perhaps the least known of all the strange reptilian forms from the Kansas chalk beds. Although Pteranodon and Nyctosaurus are known from a number of specimens, most are incomplete and more or less fragmentary. The few mounted specimens in museums are, for the most part, composite skeletons, and made up from several individuals. Whenever a paleontologist collects a Pteranodon specimen which includes a considerable portion of the skeleton, it is an event worth recording. And when a specimen is found which is so well preserved that many of the bones are still in their proper relationship to each other, or articulated, it is considered an unusual prize. Such was the good fortune of Mr. Sternberg who discovered on September 30, 1956, a Pteranodon skeleton in a small exposure of rather light buff Smoky Hill chalk some ten miles northwest of Wakeeney, Kansas. Unfortunately, the skull of this specimen is missing. General Description The discovery of this specimen was made possible by the exposure of the ends of two of the greatly elongated finger bones, the distal portions of which had been eroded away. By tracing into the chalk bluff, it was found that the outstretched wings were lying parallel to each other and some 18 to 24 inches apart. The exposed bones were the approximal half of the first phalanges. As the skeleton was carefully uncovered, it was found that the forearm bones were in place and articulated. There followed in order the long metacarpal bone, and lying beside it the splintlike metacarpals for digits 1, 2 and 3 with their phalanges terminating in the strong claws. The long metacarpal bone articulated with the carpals, which were followed by the long radius and ulna. Extending out to the side of the carpals is the slender pteroid bone which is curved a short distance from its approximal end. Above the radius and ulna is the massive humerus which fits into the glenoid socket of the fused scapulacoracoid.