Henodus

Henodus is the only placodont found in rocks that were not from the open sea, so it probably lived in brackish or freshwater lagoons.1

Its shell was made of many small bony plates that formed a mosaic pattern, unlike a turtle's shell.1

Henodus had only one tooth on each side of its mouth, and the rest of its jaws were a beak.1

It had baleen-like denticles along its jaws, similar to some whales, which helped it filter small food from the water.1

Its weak limbs suggest it spent little or no time on land.1

Scientists think Henodus could close its jaws very quickly, which helped it catch small prey.1

Small snail shells were found near the skulls of Henodus, so it might have eaten those tiny snails.2