Rhamphorhynchoid, or long tailed pterosaurs represent the more primitive form of development. Their skulls tent to be light, but relatively more massive then those of later pterosaurs. They also generally show larger teeth.
Rhamphorhynchus characterises this group of pterosaurs and the skull forms are similar in the different forms. The evidence suggests that these pterosaurs were adapted as skim feeders, spearing fish whilst flying above the water surface of lakes and large rivers.
Anurognathus is a similarly structured form, but with a short and broad skull. These types of frog mouthed pterosaurs were probably insect feeders and they were relatively small compared to the larger fish eating species.
The earliest pterosaurs, like Eudimorphodon, had some teeth with 3 cusps. It is often the case that earlier pterosaurs had variations in tooth type within then same jaw. These types of teeth could be used for cutting and shearing as well as griping and holding. Non of the pterosaurs would be able to chew food, so tearing flesh or swallowing food whole was the only realistic feeding option.