"Bowfins can be found in slower channels and oxbow lakes. Cyclurus fragosus is very similar to the modern bowfin; at over 1.5m long, Melvius is a formidable ambush predator."
―Saurian: A Field Guide to Hell Creek
Melvius was a large amiid fish from the Hell Creek Formation. Amiids are the fish that belong to the same family as modern bowfins. It seems to have been a fairly large amiid, and, like modern ones, it was probably a voracious predator, hunting smaller fish, like Lepisosteus and Lonchidion. It was adapted to the murky, under-oxigenated waters of the swamp, often breathing atmospheric air, if the water was too unbreathable.
In Saurian[]
Although no plans are known for the inclusion of Melvius in the game, it appears in the official game's artbook.