[1] Lytoceratinae is a subfamily of ammonoid cephalopods that make up part of the family Lytoceratidae.
They are characterized by shells in which the whorls bear growth lines or lamellar folds, or both, commonly corresponding to constrictions in the internal mold.
The external suture, that not lying against the previous whorl, has two lateral lobes (per side), the first being much larger.
Lytoceratinae has a long stratigraphic and temporal range (196.5 to 89.3 Ma [1]) extending from the Early Jurassic Pliensbachian to the Late Cretaceous Cenomanian, although most included genera have much shorter ranges.
Pterolytoceras and Metalytoceras from the Valanginian (Petrolytoceras may extend back to the Tithonian), Eulytoceras from the Hauterivian - Barremian, Argonauticeras and Pictetia from the Aptian - Albian.