Pterodactylus Dinosaur stl model for 3d printing.

Description: Like other pterosaurs (notably Rhamphorhynchus), Pterodactylus specimens can vary considerably based on age or level of maturity. Both the proportions of the limb bones, size and shape of the skull, and size and number of teeth changed as the animals grew. Historically, this has led to various growth stages (including growth stages of related pterosaurs) being mistaken for new species of Pterodactylus. Several detailed studies using various methods to measure growth curves among known specimens have suggested that there is actually only one valid Pterodactylus species, P. antiquus.[7]

The youngest immature Pterodactylus antiquus specimens (alternately interpreted as young specimens of the distinct species P. kochi) have a small number of teeth (as few as 15), and the teeth have a relatively broad base.[5] The teeth of other P. antiquus specimens are both narrower and more numerous (up to 90 teeth are present in some specimens).[7]

Pterodactylus specimens can be divided into two distinct year classes. In the first year class, the skulls are only 15-45mm (0.59-1.77 inches) in length. The second year class is characterized by skulls 55-95mm (2.16-3.74 inches) long, but still immature11. These first two size groups were once classified as juveniles and adults of the species P. kochi, until further study showed that even the supposed “adults” were immature, and possibly belong to a distinct genus. A third year class is represented by specimens of the “traditional” P. antiquus, as well as a few isolated, large specimens once assigned to P. kochi that overlap P. antiquus in size. However, all specimens in this third year class also show sign of immaturity. Fully mature Pterodactylus specimens remain unknown, or may have been mistakenly classified as a different genus.[5]