When discussing the saber-tooth cat being alive, Mitch's father mentions a Chilean monster closely resembling a Plesiosauria, to which Mitch explains they were "aquatic dinosaurs". Technically, dinosaurs were exclusive land animals. Plesiosauria and other aquatic reptiles, as well as flying ones such as Pterosauria, were not dinosaurs. A character as precise and fuzzy about biology such as Mitch would have never said that.