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Ammonitida is an order of more highly evolved ammonoid cephalopods that lived from the Jurassic through Cretaceous time periods, commonly with intricate ammonitic sutures.
Balearites is an extinct ancyloceratin genus included in the family Crioceratitidae, subclass Ammonoidea, from the Upper Hauterivian.
Baculina is an extinct ammonoid cephalopod genus belonging to the ancylocerid family Bochianitidae. Baculina is known from the Valanginian of the Lower Cretaceous.
Anisoceratidae is an extinct family of heteromorph ammonites which belong to the Ancyloceratina superfamily Turrilitoidea. Members of the family range is from the lower Albian to the upper Turonian. The family is possibly derived from a member of the Hamitidae.
Baculitidae is a family of extinct ammonoid cephalopods that lived mostly during the Late Cretaceous, and often included in the suborder Ancyloceratina.
Lytoceratina is a suborder of Jurassic and Cretaceous ammonites that produced loosely coiled, evolute and gyroconic shells in which the sutural element are said to have complex moss-like endings.
Ammonitina comprises a diverse suborder of ammonite cephalopods that lived during the Jurassic and Cretaceous periods of the Mesozoic Era. They are excellent index fossils, and it is often possible to link the rock layer in which they are found to specific geological time periods.
Turrilitoidea is a diverse superfamily of Cretaceous ammonites generally considered as heteromorphic and commonly included in the suborder Ancyloceratina. Shells of this diverse group do not coil planospirally, as typical for most ammonites, but rather take on a variety of unique forms. Separation of Turrilitoidea along with Ptychoceratoidea and Scaphatoidea into a different suborder, Turrilitina, was proposed by Beznosov and Mikhailova in 1983 however this view is not accepted by most authors.
Nostoceras is an extinct genus of ammonites. The etymology of the name Nostoceras comes from "nostos" meaning return and "ceros" meaning horn, named as such by Alpheus Hyatt because it bends back on itself.
Heteroceras is a Lower Cretaceous heteromorph ammonite belonging to the ancyloceratacian family, Heteroceratidae, characterized by a helically coiled juvenile shell at the apex followed by slightly curved adult shaft, with a J-shaped section at the end of it. The shell is ribbed; ribs are concave and oblique on the helix, straight and transverse on the later stages.
Zetoceras is an extinct ammonoid cephalopod genus from the suborder Phylloceratina that lived during the Early and Middle Jurassic in what is now Europe, and is included in the (family) Phylloceratidae.
Ancyloceratoidea, formerly Ancylocerataceae, is a superfamily of typically uncoiled and loosely coiled heteromorph ammonoids established by Alpheus Hyatt in 1900, that may contain as many as 11 families, depending on the classification accepted.
Acanthoceratoidea, formerly Acanthocerataceae, is a superfamily of Upper Cretaceous ammonoid cephalopods belonging to the order Ammonitida, and comprising some 10 or so families.
Eoderoceratoidea is a superfamily of true ammonites from the Lower Jurassic, comprising seven phylogenetically related families, characterized in general by having ribbed evolute shells that commonly bear spines or tubercles. Adult shell size ranges from 2 or 3 cm to giants reaching 50 cm in such genera as Apoderoceras, Epideroceras, and Liparoceras.
Perisphinctoidea, formerly Perisphinctaceae, is a superfamily of Middle Jurassic (Bajocian) to Lower Cretaceous (Barremian) ammonites, commonly with evolute shells with strong ribbing that typically divides about mid flank before crossing the venter.
Turrilites is a genus of helically coiled ammonoid cephalopods from the lower part of the Upper Cretaceous ; generally included in the Ancyloceratina. Previously it was included in the ammonoid suborder, Lytoceratina.
The Haploceratidae is the type family of the Haploceratoidea, a superfamily in the ammonitina; which according to Donovan et al. (1981) can be derived from the Taramelliceratinae, a subfamily of the Oppeliidae.
Gymnitidae is a family of Lower to Middle Triassic ammonite cephalopods with evolute, discoidal shells.
Engonoceratidae is a family of typically compressed, more or less flat sided and involute ammonites from the mid Cretaceous belonging to the Hoplitoidea. shells have flat sided outer rims ( venters), at least in some stage. Single or branching irregular ribs and variably placed tubercles may occur. Sutures have numerous auxiliary and adventive elements of similar form, in general radially arranged. Forwardly divergent saddles tend to be simple, without subdivision. Lobes, pointing apically, may be simple and undivided or may be frilled with short irregular serrations.
Ancyloceratidae is a family of heteromorphic ammonites that lived during the Early Cretaceous. Their shells begin as a loose spiral with whorls not touching which then turns into a straight shaft that ends in a J-shape hook or bend at end. Coarse ribbing and spines are common.
References
- Arkell et al 1957. Mesozoic Ammonoidea, Treatise on Invertebrate Paleontology, Part L (Ammonoidea). Geol. Soc. Amer. and Univ. Kans. press.
- Beznosov & Mikhailova,1983, in Mikhailova, I.A. and E. Yu. Baraboshkin, 2009. The Evolution of the Heteromorph and Monomorph Early Cretaceous Ammonites of the Suborder Ancyloceratina Wiedmann, Paleontological Journal, 2009, Vol. 43, No. 5, pp. 527–536.
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