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Oxynoticeratidae; Temporal range: Early Jurassic, 196.5–186.7 Ma PreꞒ Ꞓ O S D C P T J K Pg N
	Fossil of Gleviceras guabalianum from France, on display at Galerie de paléontologie et d'anatomie comparée in Paris
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Cephalopoda
Subclass:	†Ammonoidea
Order:	†Ammonitida
Suborder:	†Ammonitina
Superfamily:	†Psiloceratoidea
Family:	†Oxynoticeratidae; Hyatt, 1875

Oxynoticeratidae is a family of true ammonites (order Ammonitida) included in the superfamily Psiloceratoidea.

Oxynoticeratids have a broad, worldwide distribution but a narrow stratigraphic one, being known only from the Upper Sinemurian and Lower Pliensbachian,^[2]^[3] during which their shells changed little in form.

Genera

Cheltonia Buckman, 1904
Gleviceras Buckman, 1918
Hypoxynoticeras Spath, 1925
Oxynoticeras Hyatt, 1875
Paracymbites Spath, 1925
Paroxynoticeras Pia, 1914
Radstockiceras Buckman, 1918
Slatterites Spath, 1923

^[1]

Description

These cephalopds, as the other species in the superfamily Psiloceratoidea, are usually characterized by mostly involute, oxyconic shells with narrow venter and compressed, lanceolate whorl section. The suture line is of ammonitic type. Ribbing is feeble, hardly functional and often absent.

They have developed shorter body chambers than in the ancestral Arietitidae,^[2] resulting in more stable floating positions. Their mostly smooth, knife-edge discoidal forms would have allowed for quick, though probably no sustained, movement through the water.

Distribution

Fossils of species within this genus have been found in the Jurassic sediments of Argentina, Canada, China, France, Hungary, Italy, Mexico, Morocco, Spain, Turkey and United Kingdom.^[1]

References

^ ^a ^b ^c The Paleobiology Database
^ ^a ^b Ammonites.fr
^ Sepkoski, Jack Sepkoski's Online Genus Database – Cephalopoda Archived 2016-02-25 at the Wayback Machine

Arkell et al., 1957. Mesozoic Ammonoidea. Treatise on Invertebrate Paleontology, Part L, pp. L240-L243. Geological Soc. of America and Univ. Kansas Press.
Donovan & Callomon, 1981. Ammonoidea. [1]