Sibiritidae constitutes a family of ceratitid ammonites described in the Treatise, Part L, 1957, as ribbed or teberculate derivatives of Meekoceritidae with modification of the venter from mere widening and transverse ribbing to sulcation (being grooved). The Sibiritidae have been removed from the Noritaceae where 8 genera were included to the Ceratitaceae with some 14 genera within three defined subfamilies, as indicated. Keyserlingitinae GoricanitesOlenekoceras Olenikitinae Olenikites Silberlingitinae