Newmarracarroceras

	Newmarracarroceras ''Newmarracarroceras'' is an ammonite from the early middle Jurassic with a ribbed subinvolute shell with a keel running along the venter, or outer rim. The umbilicus is moderately wide, exposing the inner whorls exposed in part. ''Newmarracarroceras'' has a fairly wide geographic range and includes species previously described under ''Fontannesia''. Related genera include ''Asthenoceras'', ''Fontannesia, ''Guhsania ''Guhsania'' is an extinct ammonoid cephalopod genus that lived during the early Middle Jurassic (early Bajocian), from about 171.5 to 173.5 Ma. ''Guhsania'' belongs to the Sonniniidae, a member of the Hildoceratoidea Hildoceratoidea, forme ...'', and '' Witchellia''. References * Ammonitida genera Sonniniidae Ammonites of Australia Jurassic ammonites Ammonites of Europe {{ammonitina-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Sonniniidae Sonniniidae is a diverse family of Middle Jurassic ammonites ranging from those with stout evolute shells to those whose shells are sharply rimmed, oxyconic. The keel, which runs along the middle of the venter, is typically hollow. Sutures vary from simple to complex. The aptychus is shiny with coarse folds (Cornaptychus). Sonniniidae are included in the superfamily Hildoceratoidea. Most lived during the middle Bajocian stage. Distribution is worldwide except for boreal. Taxonomy Sonniniidae is divided into subfamilies with 10 genera. Sonniniidae Buckman, 1892 * Sonniniinae Buckman, 1892 *''Dorsetensia'' '' Pseudoshirbuirnia'' Dietz, 2005 '' Shirbuirnia'' '' Sonninia'' '' Sonninites'' Buckman, 1923 Witchelliinae Callomon and Chandler, 2006 *''Asthenoceras'' ''Fontannesia'' ''Guhsania'' ''Newmarracarroceras ''Newmarracarroceras'' is an ammonite from the early middle Jurassic with a ribbed subinvolute shell with a keel running along the vente ... [...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 Perisphin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
picture info	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]
	Fontannesia ''Fontannesia'' is an ammonoid cephalopod genus with a small to medium size, evolute, discoidal shell that was extant during the Jurassic Period. The sides are ribbed, the venter has a single median keel, and tubercles are lacking. ''Fontannesia'' is included in the Sonniniidae (Hildoceratoidea Hildoceratoidea, formerly Hildoceratacaea, is a superfamily of compressed or planulate ammonites, some tending to develop acute outer rims; generally with arcuate or sigmoidal ribs. Aptichus were found in place are double-valved.Arkell ''et al.' ...) and has been found widespread in Europe, western Australia, Canada, and Argentina. References * Arkell ''et al.'', 1957., Mesozoic Ammonoidea, Treatise on Invertebrate Paleontology Part L, Ammonoiea. Geological Society of America and University of Kansas Press. Ammonitida genera Sonniniidae Jurassic ammonites Ammonites of Australia {{jurassic-animal-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Asthenoceras ''Asthenoceras'' is a genus of ammonoid from the Middle Jurassic (Lower Bajocian) with dwarfish, evolute, smooth, compressed, discoidal, strongly keeled shell. ''Asthenoceras'' belongs to the Sonniniidae and may be a subgenus of the Lower Jurassic (Upper Toarcian) ''Grammoceras ''Grammoceras'' is an extinct genus of ammonite found in Yorks Ravenscar, England, from Jurassic period sediments. Its overall distribution is fairly worldwide. ''Grammoceras'' has a thin, discoidally evolute shell with simple, gently sigmoid r ...''. References * Ammonitida genera Sonniniidae Jurassic ammonites Fossils of Morocco Bajocian life {{Ammonitina-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Guhsania ''Guhsania'' is an extinct ammonoid cephalopod genus that lived during the early Middle Jurassic (early Bajocian), from about 171.5 to 173.5 Ma. ''Guhsania'' belongs to the Sonniniidae, a member of the Hildoceratoidea Hildoceratoidea, formerly Hildoceratacaea, is a superfamily of compressed or planulate ammonites, some tending to develop acute outer rims; generally with arcuate or sigmoidal ribs. Aptichus were found in place are double-valved.Arkell ''et al.' ... superfamily. The shell (conch): essentially involute and ribbed throughout, umbilical edge sharp, outer whorl oxyconic.Treatise on Invertebrate Paleontology, Part L, 1957. p.L270 References Ammonitida genera Sonniniidae Middle Jurassic ammonites {{ammonitina-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Ammonitida Genera 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 Perisphinc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
picture info	Ammonites Of Australia 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 Pom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
picture info	Jurassic Ammonites 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]