Leiophyllites

	Leiophyllites ''Leiophyllites'' is a genus of early to middle Triassic 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 cuttle ...s belonging to the family Ussuritidae, possibly forming an evolutionary link between Lower Triassic and later members of the family. The shell is evolute with a very slightly embracing whorls, ovoid in cross section. Sutures have digitate lobes and monophyllic saddles, most closely resembling those of '' Palaeophyllites'' except lobes are more flared at the ends and saddles are constricted at the base. References * W.J. Arkell ''et al.'', 1957. Mesozoic Ammonoidea, Treatise on Invertebrate Paleontology, Part L. Geological Society of America and University of Kansas Press Ammonitida genera Triassic ammonites Ammonites of Europe {{ammonite-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Ussuritidae Ussuritidae are ancestral, Triassic, Phylloceratina characterized by generally smooth, discoidal, evolute shells with rounded venters and little or no ornamentation and by sutures with primitive monophyllitic saddles with a single terminal branch or leaflet.Treatise on Invertebrate Paleontology Part L Mollusca 4, Ammonoidea The Ussuritidae are most likely derived from the Dieneroceratidae and give rise to the Discophyllitidae. Seven genera are included: '' Ussurites'' '' Palaeophyllites'' '' Monophyllites'' '' Majsvarites'' ''Leiophyllites ''Leiophyllites'' is a genus of early to middle Triassic 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 clo ...'' '' Eopsiloceras'' '' Eophyllites'' Genera are distinguished on the basis of shell morphology and characteristics of the suture. Ussuritidae are also known as the Monophylliti ... [...More Info...] [...Related Items...] OR:* [Wikipedia] [Google] [Baidu]
picture info	Ammonoidea 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Palaeophyllites ''Palaeophyllites'' is a genus of ammonoids from the Lower Triassic and a contemporary of the related ussuritid '' Eophyllites''. The shell of ''Palaeophyllites'' is evolute, inner whorls generally smooth, outer whorl with irregular ribs. Sutures are basically ceratitic with digitate lobes and simple rounded monophyllic saddles. ''Paleophyllites'' differs from contemporary Eophyllites in having ribs on the outer part of the terminal whorl and lobes that are more quadrate in outline. Like ''Eophyllites'', ''Palaeophyllites'' is ancestral to genera like '' Ussurites'' and '' Monophyllites''. References * W.J. Arkell ''et al.'', 1957. Mesozoic Ammonoidea, Treatise on Invertebrate Paleontology, Part L. Geological Society of America and University of Kansas Press Sepkoski's list of Cephalopod Genera Ammonitida genera Triassic ammonites Ammonites of Europe {{ammonite-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	Triassic Ammonites The Triassic ( ) is a geologic period and system which spans 50.6 million years from the end of the Permian Period 251.902 million years ago ( Mya), to the beginning of the Jurassic Period 201.36 Mya. The Triassic is the first and shortest period of the Mesozoic Era. Both the start and end of the period are marked by major extinction events. The Triassic Period is subdivided into three epochs: Early Triassic, Middle Triassic and Late Triassic. The Triassic began in the wake of the Permian–Triassic extinction event, which left the Earth's biosphere impoverished; it was well into the middle of the Triassic before life recovered its former diversity. Three categories of organisms can be distinguished in the Triassic record: survivors from the extinction event, new groups that flourished briefly, and other new groups that went on to dominate the Mesozoic Era. Reptiles, especially archosaurs, were the chief terrestrial vertebrates during this time. A specialized subgroup of archosaurs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]