Hyneria was a fish that lived in the Devonian period. If the Evolution of Humans was written as a story, then the main antagonist in the Devonian period would likely be this monstrosity. Originally they found pieces of crushed skull and scales in 1950, and it was later named and described in 1968. This creature was featured in Walking with Monsters, a BBC documentary about life before dinosaurs.
Hyneria brutally murdering a shark.