Skull Ornamentation

It is often very difficult to interpret the reason for skeletal ornamentations in the fossil record because it is often related to behavior and behavior must always be inferred from the fossil record.

The Case for Pteranodon sternbergi

Pteranodons are large Pterodactyloid pterosaurs and their skull is dominated by a huge crest. A study was recently conducted on a large fossil population found in France. The skeletons were examined and the crests measured. The fossils could be grouped into two distinct sizes: small and large. Upon further examination the smaller sized Pteranodons had a slightly wider pelvis which is evidence for egg laying. This would indicate that the smaller Pteranodons were female. The size of the crest also varied in the population. The smaller crests were associated with the females and the larger crests belonged to the larger male Pteranodons. This would suggest that in the case of Pteranodon the crest was used a sexual display device. It is also possible that the crest was used as identification within the population, as evidence suggests that Pteranodon sternbergi lived in vast colonies.

In Rhamphorhynchoids, the skull lacks complex ornamentation and the jaw always contains teeth. Conversely the Pterodactyloids have complex skull ornamentations and the jaw may or may not contain teeth.

It has been suggested that the crest may have helped to slow down the animal when landing or helped in steering.



© Patrick Lyons 1998.