Myopsida

Myopsida is one of the four orders of squid. It includes two families: the monotypic Australiteuthis and the diverse and commercially important Loliginidae, which has around 50 species. Some taxonomists classify this group as a suborder called Myopsina, placing it within the order Teuthida, because Myopsina and Oegopsina do not form a clear group together.

Members of Myopsida have special features that set them apart from other squid. Their eyes lack a secondary eyelid and are covered by a thin, clear membrane. Their arms and tentacles have simple suckers but no hooks. They also have a tentacle pocket on their heads and lack certain muscles near their funnel. Females have extra glands that help with egg production, but they do not have a right oviduct.

These squid live in coastal waters around the world, usually close to the ocean floor where they hunt for food. They are eaten by many sea animals, including birds. Sizes vary greatly, from tiny species that grow to less than 2 centimeters to larger ones like Loligo forbesii, which can reach almost a meter in length.

Recently, scientists found very old fossils of these squid. Before 2025, the oldest fossils were from the early Eocene in North America. But in 2025, scientists discovered well-preserved fossils from the Late Cretaceous in Japan, and another fossil from the Oligocene in Russia, showing that these squid have been around for a very long time.