Megalampris

Megalampris is an extinct genus of prehistoric opah from the late Oligocene of New Zealand about 26 million years ago. It is only known from one species, which is called Megalampris keyesi. 
Description.
"Megalampris" was a marine fish with a big head highly reminiscent of a pycnodont. It looked different from today's opahs, having a dorsal fin resembling a swordfish, and having two fins below.