When seabirds became extinct, the skies became an available niche, which became occupied by Ocean Flish. They have evolved over millions of years from a fish-like ancestor. They are not like fish that we know, but have developed true flight, just as successfully as birds and bats did.
Ocean Flish live in groups and make their nests on land. They have powerful protruding jaws and breathe air.
Their skin is tough and protective. Fins which have become powerful wings allow them to fly fast across the surface of the sea.
Flying across the ocean, they use their protusile jaws to snap up Silverswimmers or plankton from just below the surface.