Xiphactinus audax

A large predatory ray-finned fish of the Cretaceous Western Interior Seaway, Xiphactinus would have terrorized other fish it ran into. Unlike its smaller relative Ichthyodectes, which had rows of small, even teeth, Xiphactinus had fanged teeth that were clearly utilized for macropredation (eating larger fish). Several Xiphactinus are preserved with their last meals still inside them, producing “fish-within-a-fish” fossils of prey that was swallowed whole.