you should search for the "Goblin shark" Mitsikurina owstoni, and "Megamouth shark" Megachasma pelagios
or the extinct sharks like "stethacanthus", "helicoprion", "hybodus", "edesteus", "falcatus", "xenacanthus",
or "iniopteryx" and "cladoselache"
Its funny how many biologists believe that sharks have not changed much in millions of years...but the truth
of the matter is that they really have...and still are. "Hammerhead sharks" are among the latest sharks to evolve
on our planet...making them relatively recent additions to the shark family.
Other fun living fish to check out are:
"Oarfish", "Sunfish", "Fluke" & "Flounder", "Viperfish" & "dragonfish", "Anglerfish", "hagfish" & "lampreys", "tripod-fish",
"stargazers", "stonefish", "mudskippers", "lungfish", and the thought-to-be extinct "Coelocanths"
Another cool group of fish that is totally extinct and have no known living relatives are are the "placoderms", and the "arthrodires"
Hope this helps Bernard