Scaphitoidea
Scaphitidae is a family of extinct cephalopods belonging to the family of heteromorph ammonites (suborder Ancyloceratina). There is a possible fossil record of them being the last ammonites with fossils dating to the Danian of the Paleocene in Denmark, The Netherlands, The US and Turkmenistan. Genera Scaphitidae Gill, 1871 *Subfamily Otoscaphitinae Wright, 1953 **''Yezoites'' Yabe, 1910 *Subfamily Scaphitinae Gill, 1871 **''Acanthoscaphites'' Nowak, 1911 **''Clioscaphites'' Cobban, 1951 **''Discoscaphites'' Meek, 1870 **'' Eoscaphites'' Breistroffer, 1947 **''Hoploscaphites'' Nowak, 1911 **'' Indoscaphites'' Spath, 1953 **''Jeletzkytes'' Riccardi, 1983 **'' Ponteixites'' Warren, 1934 **''Rhaeboceras'' Meek, 1876 **''Scaphites ''Scaphites'' is a genus of heteromorph ammonites belonging to the Scaphitidae family. They were a widespread genus that thrived during the Late Cretaceous period. Morphology ''Scaphites'' generally have a chambered, boat-shaped shell. The init ...'' ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Ancyloceratina
The Ancyloceratina were a diverse suborder of ammonite most closely related to the ammonites of order Lytoceratina. They evolved during the Late Jurassic but were not very common until the Cretaceous period, when they rapidly diversified and became one of the most distinctive components of Cretaceous marine faunas. They have been recorded from every continent and many are used as zonal or index fossils. The most distinctive feature of the majority of the Ancyloceratina is the tendency for most of them to have shells that are not regular spirals like most other ammonites. These irregularly-coiled ammonites are called heteromorph ammonites, in contrast to regularly coiled ammonites, which are called homomorph ammonites. Biology The biology of the heteromorph ammonites is not clear, but one certainty is that their uncoiled shells would have made these forms very poor swimmers. Open shells, particularly ones with spines and ribs, create a lot of drag; but more importantly, the orient ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Scaphites
''Scaphites'' is a genus of heteromorph ammonites belonging to the Scaphitidae family. They were a widespread genus that thrived during the Late Cretaceous period. Morphology ''Scaphites'' generally have a chambered, boat-shaped shell. The initial part (juvenile stage) of the shell is generally more or less involute (tightly coiled) and compressed, giving no hint of the heteromorphic shell form yet to come. The terminal part (adult stage) is much shorter, erect, and bends over the older shell like a hook. They have transverse, branching ribs with tubercles (small bumps) along the venter. Reconstructions of the body within the shell can be made to portray ''Scaphites'' as either a benthic (bottom-dwelling) or planktonic animal, depending on where the center of gravity is located. Since useful fossils of the soft-body parts of cephalopods are highly rare, little is known about how this animal actually fit into its shell and lived its life. Age Because ''Scaphites'' and its relati ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Early Cretaceous
The Early Cretaceous ( geochronological name) or the Lower Cretaceous (chronostratigraphic name), is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 145 Ma to 100.5 Ma. Geology Proposals for the exact age of the Barremian-Aptian boundary ranged from 126 to 117 Ma until recently (as of 2019), but based on drillholes in Svalbard the defining early Aptian Oceanic Anoxic Event 1a (OAE1a) was carbon isotope dated to 123.1±0.3 Ma, limiting the possible range for the boundary to c. 122–121 Ma. There is a possible link between this anoxic event and a series of Early Cretaceous large igneous provinces (LIP). The Ontong Java-Manihiki-Hikurangi large igneous province, emplaced in the South Pacific at c. 120 Ma, is by far the largest LIP in Earth's history. The Ontong Java Plateau today covers an area of 1,860,000 km2. In the Indian Ocean another LIP began to form at c. 120 Ma, the Kerguelen P ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Clioscaphites
''Clioscaphites'' is an extinct genus of ammonite belonging to the family Scaphitidae. Species in this genus are important index fossils of the Western Interior Seaway of the Coniacian to Santonian Ages of the Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of .... References Mesozoic animals Scaphitidae Late Cretaceous ammonites of North America {{Ammonite-stub ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Rhaeboceras
''Rhaeboceras'' is an extinct genus of ammonite belonging to the subfamily Scaphitinae. Species belonging to the genus lived during the Cretaceous and have been found in the Pierre Shale The Pierre Shale is a geologic formation or series in the Upper Cretaceous which occurs east of the Rocky Mountains in the Great Plains, from Pembina Valley in Canada to New Mexico. The Pierre Shale was described by Meek and Hayden in 1862 in th ... of North America. Taxonomy The genus ''Ponteixites'' is currently deemed a junior synonym of ''Rhaeboceras'', with most specimens formerly assigned to ''Ponteixites'' appearing to be juveniles. The finding of a larger fossil specimen assigned to ''P. robustus'' similar to these juvenile remains provides evidence supporting this lumping. References Cretaceous ammonites Scaphitidae {{Ammonite-stub ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Jeletzkytes
''Jeletzkytes'' is an extinct genus of scaphatoid ammonite from the Upper Cretaceous (Maastrichtian) of North America named and described by Riccardi, 1983. In overall form ''Jeletzkytes'' closely resembles the genus ''Scaphites ''Scaphites'' is a genus of heteromorph ammonites belonging to the Scaphitidae family. They were a widespread genus that thrived during the Late Cretaceous period. Morphology ''Scaphites'' generally have a chambered, boat-shaped shell. The init ...''. A number of species have been described in the genus including: *''J. brevis'' *''J. compressus'' *''J. crassus'' *''J. criptonodosus'' *''J. dorfi'' *''J. furnivali'' *''J. nebrascensis'' *''J. nodosus'' *''J. spedeni'' References Jeletzkytes Paleobiology Database. 13 Mar. 2013. * Neil H. Landman, Karl M Waage (Karl Mensch); Scaphitid ammonites of the Upper Cretaceous (Maastrichtian) Fox Hills Formation in South Dakota and Wyoming. Bulletin of the AMNH ; no. 215, 1993 Ammonitida genera Scaphiti ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Discoscaphites
''Discoscaphites '' is an extinct genus of ammonite. This genus may have been one of the few to have briefly survived the K-Pg mass extinction. Distributions Cretaceous of Greenland, Alabama, Arkansas, California, Colorado, Kansas, Maryland, Mississippi, Missouri, New Jersey, South Dakota, Tennessee, Texas, Wyoming, and North Carolina. ''Discoscaphites'' is present in the famous Pinna Layer of the Tinton Formation of New Jersey (above the iridium anomaly The term iridium anomaly commonly refers to an unusual abundance of the chemical element iridium in a layer of rock strata at the Cretaceous–Paleogene (K–Pg) boundary. The unusually high concentration of a rare metal like iridium is often tak ...), with even possible records in the layer above, along with ''Eubaculites''. some researchers prefer a conservative interpretation when dating the Pinna Layer, the other remains still suggest ''Discoscaphites'' was a K-Pg survivor, albeit restricted to 65 Ma. References Exter ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |