Cenoceras Temporal range: | |
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Restoration | |
Fossil of Cenoceras species from Mahajanga, Madagascar | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Mollusca |
Class: | Cephalopoda |
Subclass: | Nautiloidea |
Order: | Nautilida |
Family: | Nautilidae |
Genus: | † Cenoceras Hyatt, 1884 |
Cenoceras (meaning "recent horn") is an extinct genus within the cephalopod mollusc family Nautilidae, which in turn makes up part of the superfamily Nautilaceae. This genus has been described by Hyatt in 1884. The type species is Cenoceras intermedium, which was originally described by Sowerby 1816 as Nautilus intermedius. [1]
Shells of these nektonic carnivores are variable in form, depending on species; ranges from evolute to involute, compressed lenticular to globose with rounded to flattened venter and flanks. The suture generally has shallow ventral and lateral lobes. The location of the siphuncle is variable, but never at an extreme ventral or dorsal position (Kümmel 1964, K449).
Cenoceras has a fossil range from the Upper Triassic, Carnian age to the Middle Jurassic, Callovian age (from 235.0 to 163.5 Ma). [3] [4]
Stephanoceras is an extinct genus of Stephanoceratoid ammonite which lived during the Bajocian. It is the type genus of the family Stephanoceratidae.
Phaulostephanus is an extinct genus from the ammonoid family Stephanoceratidae, which is part of the ammonitid superfamily Stephanoceratoidea, that lived during the early Middle Jurassic.
Normannites is a strongly ribbed evolute Middle Jurassic genus of ammonite included in the stephanoceratoid family Stephanoceratidae.
Nannolytoceras is an extinct genus of lytoceratid ammonite, family Lytoceratidae, with a stratigraphic range extending from the Bajocian age to Bathonian age.
Acanthonautilus is an extinct genus in the nautilid family Solenochildae (Aipocerataceae) from the Upper Mississippian of North America and equivalent strata in Europe, first described by Foord in 1896.
Homaloceras is an extinct nautiloid cephalopod from the Middle Devonian with a strongly curved shell, included in the nautilid family Centroceratidae.
Permoceras, the sole member of the family Permoceratidae, is a genus of coiled nautiloids with a smooth, compressed involute shell, whorls higher than wide, earlier whorls hidden from view. The venter is rounded as are the ventral and umbilical shoulders, the flanks flattened. The siphuncle is ventrally subcentral. The suture, which is most characteristic, has a deep, narrow pointed ventral lobe and large, asymmetrical pointed lobes on either side.
Jovellania is a genus of extinct prehistoric nautiloids from the order Oncocerida known from the Lower Devonian of Europe. Nautiloids form a broad group of shelled cephalopods that were once diverse and numerous but are now represented by only a handful of species in two genera.
Endolobus is an extinct genus from the nautiloid order, Nautilida. Nautiloids are a subclass of shelled cephalopods that were once diverse and numerous but are now represented by only a handful of species, including Nautilus. Endolubus is included in the family Koninckioceratidae which is part of the superfamily Tainoceratoidea.
Brevicoceras is an extinct nautiloid genus from the order Oncocerida with wide distribution in the Middle Devonian in Eastern North America, Russia and Morocco. Nautiloids form a broad group of shelled cephalopods that were once diverse and numerous but are now represented by only a handful of species in two genera.
Tithonoceras is a genus of nautiloid cephalopod from the Upper Jurassic found in the Crimea, belonging to the nautilacean family Paracenoceratidae.
Valhallites is an extinct genus in the nautiloid order Nautilida which includes the living Nautilus found in the tropical western Pacific Ocean. Valhalites belongs to the Koninckioceratidae, a family in the Tainoceratoidea, a nautilid superfamily.
Stearoceras is an extinct genus of prehistoric nautiloids from the Lower Pennsylvanian - Lower Permian with a fair worldwide distribution.(Kümmel 1964)
The Nautilaceae form one of five superfamilies that make up the Nautilida according to Bernard Kummel (1964), and the only one that survived past the Triassic. The Nautilaceae comprise six families: Nautilidae, Paracenoceratidae, Pseudonautilidae, Cymatoceratidae, Hercoglossidae, and Aturiidae. Shimanskiy (1957) separated the Paracenoceratidae and Pseudonautilidae from his near equivalent Nautilina and added them to the Lyroceratina, expanding the equivalent Clydonautiloidea and bringing it into the Jurassic. The Nautilaceae are represented by Nautilus and Allonautilus, genera included in the Nautilidae.
The Cymatoceratidae is a family of Mesozoic and early Cenozoic nautiloid cephalopods and the most abundant of their kind in the Cretaceous. They are characterized by ribbed, generally involute shells of varied forms - coiled such that the outer whorl envelops the previous one, as with Nautilus, and sutures that are variably sinuous.
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.
Procymatoceras is a nautiloid cephalopod from the Middle Jurassic with a large, tightly involute, rapidly expanding shell. Early, inner, whorls are round in cross section. Later, outer, whorls, and mature living chamber are flattened on the sides and venter. Surface covered with sinuous ribs. Sutures have shallow ventral and dorsal lobes. Probably gave rise to Cymatonautilus and is the likely ancestor of Cymatoceras and Paracymatoceras. Procymatoceras has its origin in the earliest Nautilidae, in Cenoceras.
Cymatoceras is a wide-ranging extinct genus from the nautilitacean cephalopod family, Cymatoceratidae. They lived from the Late Jurassic to Late Oligocene, roughly from 155 to 23 Ma.
Calliphylloceras is an ammonite belonging to the Phylloceratidae.
Plesioteuthis is an extinct genus of squids, belonging to the family Plesioteuthididae. This genus was first described in 1859, and its fossils were found in the well-known Solnhofen field in Germany.