Psephoderma (meaning "pebbly skin" in Greek) is a species of aquatic reptiles from the Triassic period, about 210 million years ago. Its teeth were specialized for crushing the shellfish it ate. Despite its tortoise-like shell, it is not related with turtles. It is actually a placodont, a type of turtle-like marine reptiles that also included Henodus.
Wikipedia has a more detailed and comprehensive article on Psephoderma
Games
Jurassic Park: Builder
Psephoderma is a silver-league crustaceavorous aquatic creature that is unlocked in Jurassic Park: Builder, and one of the creatures that have regular availability in the game.
Jurassic World: The Game
Psephoderma is a super rare non-hybrid reef aquatic that is unlocked in Jurassic World: The Game. The creature's name was spelled as Psephodfrma, which is a typo, but this appears to have recently been fixed.
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