| Stephanoceratidae Temporal range: Middle Jurassic–Upper Jurassic |
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|---|---|
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Mollusca |
| Class: | Cephalopoda |
| Subclass: | †Ammonoidea |
| Order: | †Ammonitida |
| Superfamily: | †Stephanocerataceae |
| Family: | †Stephanoceratidae |
Sephanoceratidae is a family of planulate and coronate ammonites within the Stephanocerataceae. (Arkell et al 1957) Shells are evolute so that all whorls are exposed and have strong ribbing that bifurcates, that is splits in two, on the flanks. Many have tubercles at the point of bifurcation. Whorl sections are generally subequant; the outer rim, or venter, commonly rounded (ibid)
The Sephanoceratidae are derived from the Otoitidae. Their fossils are found in upper Middle- and lower Upper Jurassic sediments.