Australiceras is an extinct ammonite genus from the upper part of the Early Cretaceous, Aptian stage, included in the family Ancyloceratidae.
Karamaiceras is an extinct cephalopod genus belonging to the Ammonoidea that lived during the Early Cretaceous. Its shell is involute, smooth and rather compressed, with the outer whorl strongly embracing the inner whorls. Sides are flattish to slightly convex and slope inwardly toward a narrowly rounded venter.
Aioloceras is an ammonite, order Ammonitida, from near the end of the Early Cretaceous. The shell is compressed with the outer whorl covering much of the previous. Sides are slightly convex, converge toward a narrowly ached venter. Inner whorls have sharp falcoid ribs, outer are smooth. Umbilical tubercles are lacking. Similar related forms include Neosaynella and Cleoniceras.
Analytoceras is an extinct genus of cephalopod belonging to the Ammonite subclass that lived during the early Jurassic. Analytoceras, named by Alpheus Hyatt in 1900, is a lytoceratid and only member of the pleuroacanthitid subfamily Analytoceratinae, which has the same characters as its genus.
Aulacostephanus is an extinct ammonoid cephalopod genus from the Upper Jurassic Tithonian belonging to the perisphinctoidean family Aulacostephanidae.
Argonauticeras is an extinct ammonoid cephalopod genus that lived during the latter part of the Early Cretaceous, included in the Lytoceratida and found in lower and possibly middle Aptian marine sediments. It has been thought of as a subgenus of Ammonoceratites.
Barroisiceras is an acanthoceratacean ammonite from the Upper Cretaceous, Coniacian, included in the family Collignoniceratidae.
Berniceras is an extinct ammonite genus from the order Ammonitida that lived during the early Oxfordian stage of the Late Jurassic. Berniceras is included in the ammonite family, Oppeliidae.
Benacoceras is a strongly ribbed, evolute ammonite from the Late Jurassic, coiled so that all whorls are exposed. Ribbing is biplicate, with very short secondaries. The venter, the outer rim, is smooth, at least on the outer whorl.
Bradfordia is a moderately involute to involute genus included in the ammonoid cephalopod family Oppeliidae, coiled so that the outer whorl encloses most, or much, of the previous, but with a small umbilicus exposing inner whorls. The shell is compressed, whorl height much greater than width, extending well out from the contact with the adjacent inner whorl. Outer flanks are finely ribbed and the rounded venter is smooth.
Euaptetoceras is an evolute hildoceratoid ammonite from the lower Middle Jurassic, included in the family Hammatoceratidae and the subfamility Hammatoceratinae. The genus may be a junior synonym for Eudmetoceras of Buckman, 1920.
Parastrenoceras is an extinct genus from the ammonoid cephalopod order Ammonitida, included in the family Spiroceratidae that lived during the Bajocian stage of the Middle Jurassic.
Oppelia is a haploceratoid ammonite and type genus for the Oppeliidae that lived during the Middle Jurassic. Shells of Oppelia are involute with a small to moderate size umbilicus, bluntly rounded to sharp venter, and deeply impressed dorsum. Sides are generally smooth but may be variously ribbed on the outer flanks. Similar and related genera include Oxycerites and Oecotraustes.
Oecotraustes is an extinct cephalopod genus included in the ammonid family Oppeliidae and named by Waagen in 1869. The genus lived during the Middle Jurassic.
Hildoceras is a genus of ammonite from the Jurassic period in the family Hildoceratidae. The shells are characterized by a narrow discoidal evolute shape, keeled venter, concave ribs along the outer flanks, and a shallow spiral groove running along smooth inner flanks. Whorls slightly overlap, cross sections are compressed. The ventral keel is bordered on either side by a shallow groove. The genus was named by Alpheus Hyatt after Saint Hilda in 1876.
Eoderoceras is an evolute, round whorled ammonite from the Lower Jurassic with an outer row of distinct spines, and in some, an inner row of tubercles, on either side; ribs only on the inner whorls.
Crucilobiceras is an ammonoid cephalopod genus from the Lower Jurassic belonging to the eoderoceratoidean family Eoderoceratidae. Cruciliboceras has an evolute shell, such that all whorls are well exposed, with persistent radial ribbing and with spines or tubercles on the outer, ventral, rim, and in some, tubercles in the inner, umbilical, rim. The genus Crucilobiceras is commonly found along the Jurassic Coast of England.
Melchiorites is a desmoceratid ammonite genus included in the subfamily Puzosiinae. Member species are characterized by an essentially evolute shell in which the early whorls are smooth, with sinuous radial or oblique constrictions but in which later whorls have feeble intermediate ribs on the outer part of the sides and venter.
Dayiceras is a finely ribbed polymorphitid eoderoceratacean ammonoid cephalopod from the Jurassic, named by Spath in 1920. The shell is evolute, coiled such that all whorls are exposed. The whorl section is compressed such as to be higher than wide. A row of fine tubercles runs along the middle of the outer rim, the venter.
Radstockiceras is an extinct genus of lower Jurassic ammonite that lived from Oxynotum zone of upper Sinemurian to Raricostatum zone of lower Pliensbachian. Shells of these animals were oxycone and involute with umbilicus that took maximum of 12% of diameter in the case of outer whorls. On inner whorls, venter has been sharp, but then it became rounded. Faint ribs had falcoid shape, but sometimes, ribs could absent. Shells could have been large in their size. Suture has been very complex, similar to Oxynoticeras, but culmination at umbilical margin has been missing. Genus has been named after town of Radstock, in Somerset.
