Syringonautilidae

The Syringonatutilidae is a family of middle and upper Triassic nautiloid cephalopods included in the Trigonoceratoidea. Derivation is from the Grypoceratadae. In turn they gave rise to the Nautilidae.

Includes Syringonautilus, Syringoceras, Clymenonautilus, Juvavionautilus, and Oxynautilus.

Shells are generally evolute, with some whorl overlap. Cross sections vary, as to suture patters reflecting differences in septa.