Pteranodon ingens

Pteranodon ingens Marsh

Pteranodon is a large crested pterosaur (flying reptile) from the Cretaceous Period of Kansas, Nebraska, and other midwestern states. Pterosaurs were not birds and not dinosaurs, but were closely related to dinosaurs. Both evolved from a common ancestor in the Late Triassic. Pteranodon was a fish-eater that soared over the shallow Cretaceous seas and coastlines, much like pelicans do today. We donít know if it had a pouch under its beak like pelicans, but some skeletons have been found with fish remains inside.

Although bones of Pteranodon were first discovered in the 1860s, it was not until after the turn of the century that we had a reasonably complete picture of the animal. Its bones are hollow and thin-walled; therefore, they were usually crushed flat. Also skeletons were generally incomplete. Like our model, it was necessary to incorporate bones from several specimens in order to reconstruct Pteranodon.

Pteranodon ingens Marsh is not the largest pterosaur. Thatís Quetzalcoatlus, with a 35- to 40-foot wingspan! It is not even the biggest known Pteranodon. That one has a wingspan of about 25 feet, and ours is closer to 22. But it is about the biggest based on reasonably complete material. It has been mounted banking into a left turn: the left wing is slightly contracted (you can see this well from above and below), the right wing is higher than the left, the head is looking a little to the left, and the body is pitched slightly forward in descent.

An Optical Illusion

Pteranodon has a rather odd appearance. The hindlimbs seem pretty spindly, but if you compare them to the torso youíll see that theyíre actually quite large, much like those of a bird or other dinosaur. The size and weight of Pteranodon are something of an optical illusion. The head and crest are enormous, but the head is hollow and weighs very little. The big beak is for trapping fish, and the crest is for sexual display (those of the females are shorter, and their pelves are wider). The wing bones look really big too, so the animal appears front-heavy. But these bones are also completely hollow and the walls are only 1 mm thick. Many of the bones have holes that show that the respiratory tissue from the lungs extended into these bones, as in birds. This would have worked to cool the blood from the exertions of flight.

Why are the bones so large and yet so thin? It turns out that these bones donít need to withstand compressive forces (as the legs do), but they do have to withstand the tensile and torsional forces of flight. The ability to do that depends almost entirely on the diameter of the bone, not on the thickness. So the bones may appear to be thick, but they weighed next to nothing. The whole animal probably didnít tip the scales at more than 20 to 25 lbs. Thus Pteranodon is something of an optical illusion. Appearances are not always what they seem.

Pteranodon ingens is located on the first floor of the Valley Life Sciences Building in the circular stairwell. He is soaring above the T. rex on the ground floor. Stop by for a closer look. To learn more about pterosaurs, see the virtual pterosaur exhibit.

Directions and times for the Valley Life Sciences Building (VLSB).