Here are color pencil drawings of two geni of prehistoric fish. Their fossils have been found in central Europe in rocks dating to the late Triassic Period. Both of these fish belong to a group called the pycnodonts, and it seems that they fed primarily upon mollusks and small crustaceans. Pycnodonts first appeared during the late Triassic Period, and became completely extinct during the Eocene Epoch of the Tertiary Period.
The first one is called Brembodus ridens. Among its features was a short spike on its back formed by extensions of the skull bones. This might have been meant to deter predators, like a modern-day triggerfish.
The second fish is called Eomesodon liassicus. It looked remarkably similar to a modern-day tang or surgeonfish, except I’m not sure if the typical surgeonfish caudal blade (a sharp pointed piece of bone, located on both sides of the base of the tail, which could be extended if needed) has been found in association with specimens of this particular genus. As to the color, it’s pure guesswork on my part.
Hope you enjoy, and I look foward to any feedback.