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Gleviceras
''Gleviceras'' is an ammonite genus (order Ammonitida) that lived during the Early Jurassic Period, found in Canada, Hungary, Mexico and the United Kingdom. ''Glevumites'' Buckman 1924, ''Guibaliceras'' Buckman 1918, ''Riparioceras'' Schindewolf 1962, ''Tutchericeras'' Buckman 1919, and ''Victoriceras'' Buckman 1918 are considered synonyms. Description ''Gleviceras'' produced laterally compressed involute shells with a small umbilicus, close spaced sinuous ribbing, and a sharp keel along venter. The suture in ammonitic with deep narrow complex lobes. It is similar to ''Oxynoticeras'' except for being less narrow and having a more rounded venter. ''Fastigiceras'' differs primarily in having an occluded umbilicus. Taxonomy ''Gleviceras'' was described by Buckman in 1918 and is included in the Family Oxynoticeratidae and superfamily Psiloceratoidea. Species include: * ''Gleviceras doris'' Reynes, 1879 * ''Gleviceras guibalianum'' D'orbigny, 1844 * ''Gleviceras iridescens'' Tutch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxynoticeratidae
Oxynoticeratidae is a family of true ammonites (order Ammonitida) included in the superfamily Psiloceratoidea. Oxynoticeratids have a broad, worldwide distribution but a narrow stratigraphic one, being known only from the Upper Sinemurian and Lower Pliensbachian,Sepkoski, JacSepkoski's Online Genus Database – Cephalopoda during which their shells changed little in form. Genera *''Cheltonia'' Buckman, 1904 *''Gleviceras'' Buckman, 1918 *''Hypoxynoticeras'' Spath, 1925 *''Oxynoticeras'' Hyatt, 1875 *''Paracymbites'' Spath, 1925 *''Paroxynoticeras'' Pia, 1914 *''Radstockiceras'' Buckman, 1918 *''Slatterites'' Spath, 1923 Description These cephalopds, as the other species in the superfamily Psiloceratoidea, are usually characterized by mostly involute, oxyconic shells with narrow venter and compressed, lanceolate whorl section. The suture line is of ammonitic type. Ribbing is feeble, hardly functional and often absent. They have developed shorter body chambers than in the ances ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ammonite
Ammonoids are a group of extinct marine mollusc animals in the subclass Ammonoidea of the class Cephalopoda. These molluscs, commonly referred to as ammonites, are more closely related to living coleoids (i.e., octopuses, squid and cuttlefish) than they are to shelled nautiloids such as the living ''Nautilus'' species. The earliest ammonites appeared during the Devonian, with the last species vanishing during the Cretaceous–Paleogene extinction event. Ammonites are excellent index fossils, and linking the rock layer in which a particular species or genus is found to specific geologic time periods is often possible. Their fossil shells usually take the form of planispirals, although some helically spiraled and nonspiraled forms (known as heteromorphs) have been found. The name "ammonite", from which the scientific term is derived, was inspired by the spiral shape of their fossilized shells, which somewhat resemble tightly coiled rams' horns. Pliny the Elder ( 79 AD near Pomp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ammonitida
Ammonitida is an order of ammonoid cephalopods that lived from the Jurassic through Paleocene time periods, commonly with intricate ammonitic sutures. Ammonitida is divided into four suborders, the Phylloceratina, Lytoceratina, Ancyloceratina, and Ammonitina. The Phylloceratina is the ancestral stock, derived from the Ceratitida near the end of the Triassic. The Phylloceratina gave rise to the Lytoceratina near the beginning of the Jurassic which in turn gave rise to the highly specialized Ancyloceratina near the end of the Jurassic. Both the Phylloceratina and Lytoceratina gave rise to various stocks combined in the Ammonitina. These four suborders are further divided into different stocks, comprising various families combined into superfamilies. Some like the Hildoceratoidea and Stephanoceratoidea are restricted to the Jurassic. Others like the Hoplitoidea and Acanthoceratoidea are known only from the Cretaceous. Still others like the Perisphinctoidea are found in both. R ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jurassic
The Jurassic ( ) is a Geological period, geologic period and System (stratigraphy), stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately Mya. The Jurassic constitutes the middle period of the Mesozoic, Mesozoic Era and is named after the Jura Mountains, where limestone strata from the period were first identified. The start of the Jurassic was marked by the major Triassic–Jurassic extinction event, associated with the eruption of the Central Atlantic magmatic province, Central Atlantic Magmatic Province. The beginning of the Toarcian Stage started around 183 million years ago and is marked by an extinction event associated with widespread Anoxic event, oceanic anoxia, ocean acidification, and elevated temperatures likely caused by the eruption of the Karoo-Ferrar, Karoo-Ferrar large igneous provinces. The end of the Jurassic, however, has no clear boundary with the Cretaceous and i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Psiloceratoidea
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. Psiloceratoidea is probably derived from the family Ussuritidae, which were Triassic members of Phylloceratoidea. Similar to their ancestors, Psiloceratidae kept smooth, rounded venter for whole of their life. Schlotheimiidae were different, as they had ventral chevrons. Rest of the families had angular venter, or keel for at least part of their ontogeny. Most of the members of this superfamily had only simple ribs, but few of them have evolved also secondary ribbing. While some members are involute and some Oxynoticeratidae were oxycone, most of the species were evolute. Families *Psiloceratidae - Evolute shells with simple, or missing ribs. An venter, there is no o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cheltonia
''Cheltonia'' is an extinct genus of ammonite from the Upper Sinemurian substage of Lower Jurassic of Europe, Africa,''Cheltonia'' at Fossilworks.org and America. It is probably a microconch of genus '' Oxynoticeras
''Oxynoticeras'' is an extinct genus of ammonite from the Early Jurassic of Europe and North America
North America is a continent in the Northern Hemisphere and almost entirely with ...
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Hypoxynoticeras
''Hypoxynoticeras'' is an extinct genus of lower Jurassic The Early Jurassic Epoch (in chronostratigraphy corresponding to the Lower Jurassic Series) is the earliest of three epochs of the Jurassic Period. The Early Jurassic starts immediately after the Triassic-Jurassic extinction event, 201.3 Ma&nb ... ammonite that lived during Jamesoni zone of lower Pliensbachian. Animals belonging to this genus had small platycone shells, of which umbilicus made 25—30% of diameter. Keel was strong and ventrolateral shoulders were prominent. It is possible, that it was just a microconch, or juvenile of '' Radstockiceras''. Distribution Fossils belonging to this genus were found in northern Germany, Poland, western Scotland and in England.Pieńkowski, G. (2014). The first Early Jurassic ammonite find in central Poland. Volumina Jurassica, 12(1), 99-104. References Oxynoticeratidae Ammonitida genera Jurassic ammonites of Europe Pliensbachian life {{ammonitina-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxynoticeras
''Oxynoticeras'' is an extinct genus of ammonite from the Early Jurassic of Europe and North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ....* ''The Elements of Palaeontology'' by Rhona M. Black This genus is characterized by its smooth shell, with almost invisible undulations on the flank, and a sharp keel.Ludvigsen, Rolf & Beard, Graham. 1997. West Coast Fossils: A Guide to the Ancient Life of Vancouver Island. pg. 83 Synonym ''Oxynotoceras'' was created by Buckman as misspelling.M. K. Howarth 2013. Treatise on Invertebrate Paleontology, Part L, Revised, Volume 3B, Chapter 4: Psiloceratoidea, Eoderoceratoidea, Hildoceratoidea. Distribution Fossils belonging to this genus were found in Europe, Morocco, Asia, Canada, USA and South America. References Oxynoticerat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paracymbites
''Paracymbites'' is an extinct genus of lower Jurassic The Early Jurassic Epoch (in chronostratigraphy corresponding to the Lower Jurassic Series) is the earliest of three epochs of the Jurassic Period. The Early Jurassic starts immediately after the Triassic-Jurassic extinction event, 201.3 Ma&nb ... ammonite that lived during Raricostatum zone of upper Sinemurian. Animals belonging to this genus had small shells with semicircular whorl section and rounded or fastigate venter, of which umbilicus made about 25% of diameter. Last whorl could have been excentric. Keel was faint and it might have been only on the earlier part of the last whorl. Aperture had ventral rostrum. Body chamber made about 75% of whorl and was faintly plicate, or smooth. Distribution Fossils belonging to this genus were found in Great Britain, Tunisia and Morocco. References Oxynoticeratidae Ammonitida genera Jurassic ammonites of Europe Ammonites of Africa Sinemurian life {{ammonit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paroxynoticeras
''Paroxynoticeras'' is an extinct genus of lower Jurassic ammonite that lived during upper Sinemurian. Animals belonging to this genus had platyconic shells with compressed whorl section and could grow to large sizes. In the case of young specimens, umbilicum is small, but it increases in bigger specimens.. Last whorl is excentric, which can occur also in relative species, ''Paracymbites''. While on the outer whorls, venter is always rounded, on inner whorls it can be both rounded or sharp. Ornamentation on inner whorls and suture is similar to ''Oxynoticeras ''Oxynoticeras'' is an extinct genus of ammonite from the Early Jurassic of Europe and North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the ...'', but in bigger specimens, ribs became straight, simple and blunt. In these bigger specimens, midlateral tubercules might be present. Distribution Fossils belonging to thi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radstockiceras
''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.Schlegelmilch, R. (1992). Die Ammoniten des süddeutschen Lias: ein Bestimmungsbuch für Fossiliensammler und Geologen. Springer Spektrum. Distribution Fossils belonging to this genus are found in Europe, South America, North Africa and Turkey. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Slatterites
''Slatterites'' is an extinct genus of lower Jurassic The Early Jurassic Epoch (in chronostratigraphy corresponding to the Lower Jurassic Series) is the earliest of three epochs of the Jurassic Period. The Early Jurassic starts immediately after the Triassic-Jurassic extinction event, 201.3 Ma&nb ... ammonite that lived during upper Sinemurian. Animals belonging to this genus had small shells that had oxycone whorl section and sharp venter when young. In the case of older specimens, whorl section becomes oval and venter is round. This change is very quick. Last whorl is decorated by blunt ribs that can be alternating on opposite sides. Suture is by broad and simple elements similar to suture of '' Eparietites''. Distribution Fossils belonging to this genus were found in England. References Oxynoticeratidae Ammonitida genera Jurassic ammonites of Europe Sinemurian life {{ammonitina-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
