The Phyllocertina comprise a suborder of ammonoid cephalopods, belonging to the Ammonitida, whose range extends from the Lower Triassic to the Upper Cretaceous. Shells of the Phylloceratina are generally smooth with small to large umbilici and complex sutures with leaf-like phylloid saddle endings and lobes with thorn-like projections.
Frechites is an early Triassic ammonite, a kind of cephalopod with an external shell, included in the ceratitid family Beyrichitidae.
Ceratitida is an order that contains almost all ammonoid cephalopod genera from the Triassic as well as ancestral forms from the Upper Permian, the exception being the phylloceratids which gave rise to the great diversity of post Triassic ammonites.
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.
Ussurites is an extinct ammonoid cephalopod genus belonging to the suborder Phylloceratina and is included in the family Ussuritidae. Its range is restricted to the early Middle Triassic, (Anisian)
Psiloceratoidea is a superfamily of Early Jurassic ammonoid cephalopods proposed by Hyatt in 1867, assigned to the order Ammonitida. They were very successful during Hettangian and Sinemurian. Last of them, family Cymbitidae and genera Hypoxynoticeras and Radstockiceras survived into Early Pliensbachian.
The Clydonautiloidea are a superfamily within the nautiloid order Nautilida characterized by smooth, generally globular, shells with nearly straight sutures, in early forms, but developing highly differentiated sutures in some later forms. Where known, the siphuncle tends to be central to subcentral.
The Trigonoceratoidea are a superfamily within the Nautilida that ranged from the Devonian to the Triassic, thought to have contained the source for the Nautilaceae in which Nautilus is found.
Syringonautilidae is a family of Nautiloidea from the middle to late Triassic. Syringonautilidae comprise the last of the Trigonoceratoidea and are the source for the Nautilaceae which continued the Nautiloidea through the Mesozoic and into the Cenozoic right down to the recent. Syringonautilidae is a strictly Triassic family, derived early in the Triassic from the Grypoceratidae.
Grypoceratidae is the longest-lived family of the Trigonoceratoidea, or of the near equivalent Centroceratina; members of the Nautilida from the Upper Paleozoic and Triassic.
Phylloceratidae is the predominant family of the Phylloceratina with some 15 or more genera found in rocks ranging from the Lower Jurassic to the Upper Cretaceous. Members of the Phylloceratidae are characterized by smooth, involute shells with very thin walls. Many are covered with fine growth lines but are usually without ribbing. Sutures are complex with the major and minor branches of the saddles with phylloid or spatulate endings.
Juraphyllitidae is a family of Lower Triassic phylloceratin ammonites from Europe, North Africa, and Asia characterized by narrow, evolutely coiled shells, usually with coarse ventral ribbing on the body chamber. The first lateral saddles in the suture are diphyllic, with two terminal branches, others exposed sutural saddles are diphyllic or triphyllic, those covered by successive whorls being monophyllic. A few genera are more involute, with successive whorls partially embracing the flanks of the previous. All are compressed and a few lack ribbing.
The Rhiphaeoceratidae are a small family of nautilids included in the superfamily Tainocerataceae that comprises four very similar genera. These genera are characterized by a perforate umbilicus and little more than a single evolute coil. Whorl sections are oval, subquadrate, or subtrapezoidal. Sutures bend forward on the outer rim, forming wide shallow ventral saddles and dip strongly to the rear on the inner rim, forming deep dorsal lobes.
Inyoites is an ammonoid genus from the Lower Triassic, included in the ceratitid family Inyoitidae.
Brancoceratidae is a family of acanthoceratoid ammonites from the middle of the Cretaceous, recognized by their commonly evolute shells with round, oval, or quadrate whorls, strong ribs, usual ventral keels, and at least, umblical tubercles. The family is thought to be derived from the Desmoceratidae (Desmoceratoidea), perhaps from Silesitoides or some allied genus.
Monophyllites is an extinct cephalopod genus belonging to the family Ussuritidae that lived during the Triassic period, from Anisian to Ladinian age.
Rhacophyllites is an extinct genus of cephalopods belonging to the family Discophyllitidae. These nektonic carnivores lived during the Triassic period, from Carnian to Rhaetian age.
Sturia is a genus of ceratitid ammonoids from the Lower Triassic with an ammonitic suture.
Palaeophyllites is a genus of ammonoids from the Lower Triassic and a contemporary of the related ussuritid Eophyllites.
Leiophyllites is a genus of early to middle Triassic ammonites belonging to the Ussuritidae, possibly forming an evolutionary link between Lower Triassic and later members of the family.
