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Euomphaloceras
''Euomphaloceras'' is an early Upper Cretaceous ammonite genus, (Cephalopoda, Ammonoidea), included in the Acanthoceratinae until established as the type genus for the Euomphaloceratinae by Cooper, 1978. The shell is very evolute, all whorls exposed, and rather depressed, with prominent umbilical and ventrolateral tubercles on some or all main ribs. The Venter broad and flat with three rows of tubercles that are more numerous than the ventrolateral ones. May have shallow ventral constrictions. Derivation is from an evolute '' Acathoceras''. References * W.J. Arkell ''et al.'', 1957. Mesozoic Ammonoidea; Treatise on Invertebrate Paleontology The ''Treatise on Invertebrate Paleontology,'' published from 1953–2007 by the Geological Society of America and the University of Kansas, then 2009–present by the University of Kansas Paleontological Institute, is a definitive multi-authore ...,Part L, Mollusca 4. Geological Society of America and University of Kansas Press. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Euomphaloceratinae
Euomphaloceratinae is a subfamily of Upper Cretaceous ammonites included in the Acanthoceratidae, characterized by generally evolute shells with quadrate whorl sections that are strongly ribbed. Sutures are ammonitic, but not overly complex. Genera include: *'' Burroceras'' *'' Codazziceras'' *'' Euomphaloceras'', (type genus) *'' Hourcqiceras'' *'' Kamerunoceras'' *'' Lotzeites'' *'' Morrowites'' *'' Paraburroceras'' *'' Paramammites'' *'' Pseudaspidoceras'' *'' Romaniceras'' *'' Shuparoceras'' some of which have been removed from other taxa where originally placed. ''Euomphaloceras'', the type genus of the subfamily, was removed from the Acanthoceratinae sensu Arkell et al. 1957, ''Kamarunoceras'' and ''Pseuaspidoceras'' from the Mammitinae, sensu Arkell et al. 1957. Others were added since initial publication of the Treatise on Invertebrate Paleontology The ''Treatise on Invertebrate Paleontology,'' published from 1953–2007 by the Geological Society of America and t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cenomanian
The Cenomanian is, in the International Commission on Stratigraphy's (ICS) geological timescale, the oldest or earliest age (geology), age of the Late Cretaceous epoch (geology), Epoch or the lowest stage (stratigraphy), stage of the Upper Cretaceous series (stratigraphy), Series. An age is a unit of geochronology; it is a unit of time; the stage is a unit in the stratigraphic column deposited during the corresponding age. Both age and stage bear the same name. As a unit of geologic time measure, the Cenomanian Age spans the time between 100.5 and 93.9 million years ago (Mya). In the geologic timescale, it is preceded by the Albian and is followed by the Turonian. The Upper Cenomanian starts around at 95 Mya. The Cenomanian is coeval with the Woodbinian of the regional timescale of the Gulf of Mexico and the early part of the Eaglefordian of the regional timescale of the East Coast of the United States. At the end of the Cenomanian, an anoxic event took place, called the Cenomani ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ammonitida
Ammonitida, or true ammonites, are an order of Ammonoidea, 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 Peris ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acanthoceratinae
The Acanthoceratinae comprise a subfamily of ammonoid cephalopods that lived during the Late Cretaceous from the latter early Cenomanian to the late Turonian Shells are evolute, tuberculate and ribbed, with subquadrate to squarish whorl section wherein tubercles typically dominate over ribs. Derivation is from the Mantellicertinae in the early Cenomanian. Gave rise through '' Neocardioceras'' to the Mammitinae. Genera The following genera are included in the Acanthoceratinae according to various sources as indicated. *'' Acanthoceras'' Neumayer, 1875 *''Acompsoceras'' Hyatt, 1903 *'' Alzadites'' *''Benueites'' Reyment, 1954 *'' Calycoceras'' Hyatt, 1900 *'' Conlinoceras'' Cobban & Scott, 1972 *''Cunningtoniceras'' Collignon, 1937 *'' Eucalycoceras'' Spath, 1923 *'' Hypacanthohoplites'' Spath, 1923 *'' Kastanoceras'' *'' Kennediella'' *'' Microsulcatoceras'' *'' Nebraskites'' Kennedy & Cobban, 1988 *'' Neocardioceras'' Spath, 1926 *'' Nigericeras'' Schneegan, 1943 *'' Paraconl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acanthoceras (ammonite)
''Acanthoceras'' is an extinct cephalopod genus belonging to the subclass Ammonoidea and family Acanthoceratidae that lived from the Albian to early Coniacian stages of the Cretaceous.''Acanthoceras'' at .org Description Their shells had ornate ribs whose function is unknown, although some scientists have speculated that these ribs helped strengthen the animals' shells to allow them to live at greater depths where the water pressure is higher. An adult had a shell diameter of approximately .Species * ''A. athabascense'' Warren and Stelck, 1955 * ''A. chasca'' Benavides-Caceres, 1956 * ''A. compitalis''[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Treatise On Invertebrate Paleontology
The ''Treatise on Invertebrate Paleontology,'' published from 1953–2007 by the Geological Society of America and the University of Kansas, then 2009–present by the University of Kansas Paleontological Institute, is a definitive multi-authored work of currently 55 volumes, written by more than 300 paleontologists, and covering every phylum, class, order, family, and genus of fossil and extant (still living) invertebrate animals. The prehistoric invertebrates are described as to their taxonomy, morphology, paleoecology, stratigraphic and paleogeographic range. However, taxa with no fossil record whatsoever have just a very brief listing. Publication of the decades-long ''Treatise on Invertebrate Paleontology'' is a work-in-progress; and therefore it is not yet complete: For example, there is no volume yet published regarding the post- Paleozoic era caenogastropods (a molluscan group including the whelk and periwinkle). Furthermore, when needed, previously published vol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acanthoceratidae
Acanthoceratidae is an extinct Family (biology), family of Acanthoceratoidea, acanthoceratoid cephalopods in the order Ammonitida, known from the Upper Cretaceous. The type genus is ''Acanthoceras (ammonite), Acanthoceras''. Diagnosis Acanthoceratidae species are strongly tuberculate with at least umbilical and ventrolateral tubercles in most genera included. Ribs are dominant in some, in others weak or absent on the outer whorls. Most are evolute, compressed to very depressed in section. Sutures are ammonitic with little variation, but showing a tendency for simplication in later genera. Taxonomy Acanthoceratidae de Grossouvre, 1894 includes the following subfamilies. *Acanthoceratinae de Groussouvre, 1894 *Euomphaloceratinae Cooper, 1978 *Mammitinae (Hyatt, 1900) (= Fallotitinae Wiedmann, 1960; Mitoniainae Renz & Alvarez, 1979) *Mantelliceratinae Hyatt, 1903 References * Wright, W.C. 1957 Family Acanthoceratidae Hyatt in W.J. Arkell, et al. 1957. Mesozoic Ammonoidea;. Tre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cretaceous Ammonites
The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 77.1 million years, it is the ninth and longest geological period of the entire Phanerozoic. The name is derived from the Latin , 'chalk', which is abundant in the latter half of the period. It is usually abbreviated K, for its German translation . The Cretaceous was a period with a relatively warm climate, resulting in high eustatic sea levels that created numerous shallow inland seas. These oceans and seas were populated with now-extinct marine reptiles, ammonites, and rudists, while dinosaurs continued to dominate on land. The world was largely ice-free, although there is some evidence of brief periods of glaciation during the cooler first half, and forests extended to the poles. Many of the dominant taxonomic groups present in modern times can be ultimately traced back to origins in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ammonitida Genera
Ammonitida, or true ammonites, are 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 Perisph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ammonites Of North America
Ammonoids are extinct, (typically) coiled-shelled cephalopods comprising the subclass Ammonoidea. They are more closely related to living octopuses, squid, and cuttlefish (which comprise the clade Coleoidea) than they are to nautiluses (family Nautilidae). The earliest ammonoids appeared during the Emsian stage of the Early Devonian (410.62 million years ago), with the last species vanishing during or soon after the Cretaceous–Paleogene extinction event (66 million years ago). They are often called ammonites, which is most frequently used for members of the order Ammonitida, the only remaining group of ammonoids from the Jurassic up until their extinction. Ammonoids exhibited considerable diversity over their evolutionary history, with over 10,000 species having been described. Ammonoids are excellent index fossils, and they have been frequently used to link rock layers in which a particular species or genus is found to specific geologic time periods. Their fossil shells usual ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
