Belemnoids
Well preserved Phragmoteuthis, with arm hooks and outline of mantle
Scientific classification
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Cephalopoda
Subclass:	Decapodiformes
Superorder:	Belemnoidea
Orders
Aulacocerida Phragmoteuthida Belemnitida Diplobelida

Belemnite guards from the Jurassic of Wyoming, USA.

Fossil belemnite. Rostrum and phragmocone; normal sections of a rostrum (see the radial-concentrical structure of calcite fibers).

Belemnites (or belemnoids) are an extinct group of marine cephalopod, similar in many ways to the modern squid, and closely related to the modern cuttlefish.

Like them, the belemnites had an ink sac, but, unlike the squid, they had ten arms of roughly equal length, and no tentacles.

The belemnites are a monophyletic group of superorder status, called the Belemnoidea. There are four orders.