Squid or teuthids (Teuthida) are a morphological group, appeared in the early Jurassic, cuttlefish-like marine decepod cephalopods with about 300 species. Most species do not have a specific vernacular name and are therefore designated in French under the generic name “Calmar”. The same is true of the term squid, another vernacular name more particularly used when these animals are considered as edible or fishing bait, but which also designates other cephalopods, such as cuttlefish. These animals have long been grouped together in the scientific classification in the order of the Teuthida, but this one turns out to be paraphyletic and the “squid” (according to the morphological definition) are thus broken up between the orders of Myopsina and Oegopsina, the second being much larger.