Tooth Modification and Expansion
Some pterosaur species have developed tooth forms to take advantage of food resources. The advantage is clearly that they are not competing against other pterosaurs for nutrition.
Ctenochasma has a fine tooth form. This is seen in a number of similar species and is probably related to sifting small organisms for water.
This sifting jaw form is taken to extremes in the species Pterodaustro, which shows a flamingo like sieving jaw apparatus. This pterosaur must have been feeding on shrimp like animals and small crustaceans found in lakes and slow flowing shallow rivers.
Rhamphorhynchus has specialised teeth for spearing fish from the surface of lakes. this form of tooth development is seen in species such as Dorygnathus, Angustanipterus and Rhamphocephalus.
Scaphognathus has a wide jaw with teeth tightly packed at the front upper part. This sturdy skulled pterosaur shares this jaw arrangement with other species like Istiodactylus. It is likely that these species were adapted to feed on small reptiles and larger insects.