Barroisiceras is an acanthoceratacean ammonite from the Upper Cretaceous, Coniacian, included in the family Collignoniceratidae.
Gastrioceratoidea is one of 17 superfamilies in the suborder Goniatitina, ammonoid cephalopods from the Late Paleozoic.
Sholakoceras is an extinct genus of nautiloid cephalopods from the Lower Permian of southern Russia, included in the Tainoceratacean family Rhiphaeoceratidae,. The shell of Shalakoceras is evolute with a perforate umbilicus. Whorl sections are subquadrate with the ventral and lateral sides flattened and ventral and umbilical shoulders rounded. Lateral areas bear short, slightly oblique ribs. sutures form broad ventral saddles with a slight, shallow lobe, very shallow lateral lobes, and a deep funnel-shaped dorsal lobe.
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.
The Centroceratidae is the ancestral family of the Trigonoceratoidea and of the equivalent Centroceratina; extinct shelled cephalopods belonging to the order Nautilida
Stephanoceratoidea, formerly Stephanocerataceae, is a superfamily of middle- upper Jurassic ammonoid cephalopods within the order Ammonitida containing diverse forms, generally with sharp ribbing and complex suture lines. Aptychi are believed to be mostly granular (Granulaptycus) or concentrically ribbed on the surface (Praestriaptychus)
Tainonautilus is an extinct coiled cephalopod that lived during the Permian and Early Triassic which is included in the nautiloid family Tainoceratidae.
Aphelaeceras is an extinct genus from the nautilid family Trigonoceratidae which is part of the Trigonocerataceae, that lived during the Mississippian Period in the late Paleozoic.
Encoiloceras is a genus of Tainoceratids, a nautiloid cephalopod in the order Nautilida that has been found in Upper Triassic (Carnian) sediments in the Alps and Hungary.
The Rhiphaeoceratidae are a small family of nautilids included in the superfamily Tainoceratoidea 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.
Gymnites is a genus of ammonoid cephalopod from the Middle Triassic belonging to the ceratitid family Gymnitidae. These nektonic carnivores lived during the Triassic period, the Anisian age.
Hecticoceras is an ammonite genus belonging to the haploceratoid family Oppeliidae, that lived during the Middle and Late Jurassic, from the Callovian. Hecticoceras may be seen as a series of some nine subgenera, beginning with the lower Callovian H. (Hecticoceras) and H. (Hecticoceratoides) and ending with the lower Oxfordian H. (Pseudobrightia) and H. (Eochetoceras). Hecticocerassensu lato and Prohecticoceras from the underlying Bathonian form the oppeliid subfamily, Hecticoceratinae.
Cheiloceras is a subglobular to thickly lenticular goniatite with a closed umbilicus from the Upper Devonian and type genus for the Cheiloceratidae.
Megalytoceras is an extinct genus of ammonite from the middle Jurassic, belonging to the suborder Lytoceratina.
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.
Schlotheimia is a genus of extinct cephalopods belonging to the subclass Ammonoidea that lived during the Hettangian stage at the beginning of the Early Jurassic.
Ophiceras is an extinct genus of smooth, evolute ceratitid ammonites from the Griesbachian, with a rounded venter. Fossils of the genus have been found in Armenia, Azerbaijan, China, Greenland, and India.
Tragodesmoceras is a large moderately involute ammonite with deeply embracing whorls that are higher than wide, a steep sided umbilicus and a narrowly rounded venter. Ornament consists of primary ribs that begin at the umbilical shoulder and smaller secondary ribs that begin mid flank. Ribs are sigmodal, periodically thickened and bent forward on the outer flank to cross the venter as chevrons. The suture has a broad trifid lateral lobe.
