Xenoceltitidae are evolute, generally ribbed, upper Lower Triassic Ceratitida with ceratitic or goniatitic sutures; formerly included in the Noritaceae but now placed in the Xenodiscaceae.
The Xenoceltitidae are derived from the Ophiceratidae.
References
Arkell et al. 1957; Mesozoic Ammonoidea, Treatise on Invertebrate Paleontology, Part L, Ammonoiea; Geological Society of America The Paleobiology Database