Dsungaripterus weii and other similar pterosaurs exhibit an unusual tooth structure. They have thick and short crusher teeth in the mid jaw region. It is thought that they would have been suitable for crushing clams and shelled organisms like ammonites and nautiloids. The jaw would have been covered in a beak sheath.
Pterodaustro guanazui
is an unusual pterosaur insofar as its lower teeth form a fine
sieve. This pterosaur was able to filter small crustaceans
from water in very much the same way that modern day Flamingos
do. The upper jaw retains very small and short teeth along
its length.
Bonaparte J. F., 1971, Descripcion del craneo y mandibulas de Pterodaustro guinazi (Pterodactyloidea - Pterodaustriidae), de la Formacion Lagarcito, San Luis, Argentina, Publ. Mus. Mun. Cienc. Nat. Mar del Plata, Pp. 263-272
Chiappe L. M. and Chinsamy A., 1996, Pterodaustro’s true teeth. Nature 379, 211–212.
Young C. C., 1964, On a New Pterosaurian from Sinkiang, China, Vertebrate Palasiatica, vol.8 pp.221-225, Part translated into English.