Xiphactinus was a large fish that lived in the Late Cretaceous period. It was a predatory fish that could reach lengths of up to 20 feet long.
||Wikipedia has a more detailed and comprehensive article on Xiphactinus
Xiphactinus is a limited edition creature in the Aquatic Park section of Jurassic Park: Builder.
see Xiphactinus/JW: TG
Xiphactinus was added to the game as a creatable aquatic animal on the March 16, 2016 update.
Behind the scenes
In concept art for Jurassic Park: The Game, a Xiphactinus skeleton was to be on display inside the Marine Facility's rotunda, but it is absent from the finished game.