Belosaepia, occasionally incorrectly Belosepia,[1] is an extinct genus of cuttlefish-like cephalopod known from the Eocene.[2]
Species of the genus Belosaepia reached 18cm (07inches) in length and 5cm (02inches) across and had a large siphuncle that penetrated its oblique septa.[2] The shell was endogastrically coiled.[2] It had a small belemnite-like guard, which took the form of a short horn at the posterior end of the shell;[2] usually, only a small portion of the shell closest to the guard is preserved. The chambers in the shell closely resemble those present in the cuttlebone of modern cuttlefish.[2]
Belosaepia lived close to the sea floor.[2]