Phylum: Mollusca Class: Cephalopoda Subclass: Coleoidea Superorder: Decapodiformes Order: Teuthida A. Naef , 1916b Suborders † Plesioteuthididae ( incertae sedis ) Myopsina Oegopsina Squid are marine cephalopods of the order Teuthida , which comprises around 300 species. Like all other cephalopods, squid have a distinct head, bilateral symmetry , a mantle