There are many adaptations of the head and jaws of pterosaurs, so it is quite certain that different forms used different feeding methods, as birds do.
Overall, most fossils have been found in marine strata, which suggests that they could fly well over water, and that fish were on the menu for many species.
The jaws of fish-eaters was long and often held forward-pointing teeth, good for catching fish (see Anhanguera).
Remains of a last fish supper have been found in Pteranodon.

Fossils show that one pterosaur, the Pterodaustro found in Argentina, had comb-like strainers in its mouth.
The pterosaur probably ate by filling its lower jaw with water and pushing the water out of its mouth through the strainers.
The strainers could catch any plankton or other small creatures that were in the water, and when the water was gone, the animal could eat what was left.
Other species had long, compressed lower jaws, which suggest they were skimmers at the top of the water.

The other main item of diet was the insects.
Flying insects were abundant in the Mesozoic, and many pterosaur species give clear signs that this was their food.
These have a broad mouth, often with short peg-like teeth.p339–341
There are many adaptations of the head and jaws of pterosaurs, so it is quite certain that different forms used different feeding methods, as birds do. Overall, most fossils have been found in marine strata, which suggests that they could fly well over water, and that fish were on the menu for many species. The jaws of fish-eaters was long and often held forward-pointing teeth, good for catching fish (see Anhanguera). Remains of a last fish supper have been found in Pteranodon.
Fossils show that one pterosaur, the Pterodaustro found in Argentina, had comb-like strainers in its mouth. The pterosaur probably ate by filling its lower jaw with water and pushing the water out of its mouth through the strainers. The strainers could catch any plankton or other small creatures that were in the water, and when the water was gone, the animal could eat what was left. Other species had long, compressed lower jaws, which suggest they were skimmers at the top of the water.
The other main item of diet was the insects. Flying insects were abundant in the Mesozoic, and many pterosaur species give clear signs that this was their food. These have a broad mouth, often with short peg-like teeth.p339–341
Pterosaur