Spinosaurids broke from the typical blade-toothed theropod hunting style: their snouts are long and narrow, more crocodilian than typical dinosaurian in proportion, and their teeth are conical rather than serrated -- a shape better suited to gripping slippery prey than slicing flesh. Isotopic and anatomical evidence across several genera points to a diet heavy in fish, and some researchers argue for genuinely semi-aquatic habits in at least the genus Spinosaurus, though the extent of that aquatic lifestyle remains actively debated.
Spinosaurus itself, from Cretaceous North Africa, carried a dramatic sail of elongated neural spines along its back and is regularly cited among the largest predatory dinosaurs known by length. Baryonyx, discovered in England in 1983 and described by Alan Charig and Angela Milner, was the first spinosaurid found with direct evidence of fish in its stomach contents. Suchomimus, also African, rounds out the family's best-known members.