olcostephanidae

OBS: [Les Ammonites de la famille des olcostephanidae ont une] couronne de tubercules périombilicaux plus ou moins costiformes, donnant naissance à des côtes, le plus souvent fasciculées; [les] constrictions [sont] assez nombreuses coupant obliquement la costulation. [Ces ammonites sont] souvent sphaerocônes, pouvant atteindre de grandes tailles.

OBS: [Ammonites of the family olcostephanidae are] perisphinctid derivatives with umbilical tubercles and bundled ribs, normally with strong constrictions at some stage. Many inflated and involute forms occur, some being sphaerocones or cadicones. Ribs are distinct and usually dense. Besides umbilical tubercles, lateral or even ventro-lateral tubercles may be present (...) ""U.Jur(L.Tithon.)-L.Cret.(L.Barrem.)""