Placoderms were a class of prehistoric fish which sported bony amor plating over their heads and chests. These plated fish dominated in the early oceans but were eventually out competed by sharks and other non-plated fish. While their plating offered protection, it also made their energy needs higher and their swimming less agile and quick. Eventually, the last of placoderms went extinct due to extreme climate change and lower oxygen levels in the oceans.
Placoderms were a class of prehistoric fish which sported bony amor plating over their heads and chests. These plated fish dominated in the early oceans but were eventually out competed by sharks and other non-plated fish. While their plating offered protection, it also made their energy needs higher and their swimming less agile and quick. Eventually, the last of placoderms went extinct due to extreme climate change and lower oxygen levels in the oceans.