The superfamily Clydonautilaceae is revised. It is proposed that this group of Triassic nautiloids be raised to the rank of the suborder Clydonautilina on the basis of the following distinctive morphological features: their complexly dissected suture, which is unique in the nautiloids; their siphuncle with annular intrasiphonal deposits; and their unusually small "embryonic" shell that occupies the entire first whorl.
