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Anomphalidae
The Anomphalidae is an extinct family of fossil sea snails, marine gastropod mollusks. These are archaeogastropods which are included in the suborder Trochina. The Anomphalidae lived during the Paleozoic, from the Silurian to the Middle Permian. According to some authorities these snails belong instead to the Euomphalacea. Morphologic diagnosis Shells of the Anomphalidae are rounded, almost discoidal, low-spired trochospiral inform, possibly with a globular body whorl. The aperture is oval, without exhalent slit or crease. The umbilicus is narrow, open or closed. The inner shell layer is seemingly nacreous. The shell surface is generally smooth, ornamentation consisting of fine transverse lyrae or growth lines parallel to the aperture lip.J. Brooks Knight et al 1960. Systematic Descriptions (Gastropoda), Treatise on Invertebrate Paleontology, Part I, Mollusca 1, R.C. Moore (ed). The Anomphalidae differ from the Euomphalcea to which they have been reassigned in being more tr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Euomphaloidea
Euomphaloidea, originally Euomphalacea, is an extinct superfamily of marine molluscs that lived from the Early Ordovician to the Late Cretaceous, included in the Gastropoda Moore R. C., Lalicker & Fischer (1952). ''Invertebrate Fossils''. McGraw-Hill publisher. but speculated as instead perhaps Monoplacophora. Description Euomphaloid shells are mostly discoidal and may be either orthostrophic (coils wrapped around an erect cone) or hyperstrophic (coils wrapped around an inverted cone); are widely umbilicate and commonly have a channel, presumed exhalent, within the angulation in the outer part of the upper whorl surface. The shell wall is relatively thick, with an external prismatic layer of calcite, which may be pigmented, and an internal layer of lamellar, but not nacreous, aragonite.(1960). ''Treatise on Invertebrate Paleontology. Part I, Gastropoda. Taxonomy As with almost all fossils, the taxonomic relations of and within the euophaloids can only be inferred from their rem ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anomphalus
''Anomphalus jaggerius'' is an extinct species of Permian sea snail. Fossils have been found in Artinskian era limestone from the Bird Spring Formation in the southern Arrow Canyon Range of the US State of Nevada. The species, which had a shell wide, was a subtidal epifaunal grazer. It was named after Rolling Stones lead singer Mick Jagger. See also *''Aegrotocatellus jaggeri'' - a species of trilobite named after Jagger *''Jaggermeryx naida'' - a species of Miocene ungulate named after Jagger *''Perirehaedulus richardsi'' - a species of prehistoric Prehistory, also known as pre-literary history, is the period of human history between the use of the first stone tools by hominins 3.3 million years ago and the beginning of recorded history with the invention of writing systems. The use of ... trilobite named after British musician Keith Richards * List of organisms named after famous people (born 1900–1949) References External links * Permian ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Silurian
The Silurian ( ) is a geologic period and system spanning 24.6 million years from the end of the Ordovician Period, at million years ago ( Mya), to the beginning of the Devonian Period, Mya. The Silurian is the shortest period of the Paleozoic Era. As with other geologic periods, the rock beds that define the period's start and end are well identified, but the exact dates are uncertain by a few million years. The base of the Silurian is set at a series of major Ordovician–Silurian extinction events when up to 60% of marine genera were wiped out. One important event in this period was the initial establishment of terrestrial life in what is known as the Silurian-Devonian Terrestrial Revolution: vascular plants emerged from more primitive land plants, dikaryan fungi started expanding and diversifying along with glomeromycotan fungi, and three groups of arthropods (myriapods, arachnids and hexapods) became fully terrestrialized. A significant evolutionary milestone during ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Umbilicus (mollusc)
The umbilicus of a shell is the axially aligned, hollow cone-shaped space within the whorls of a coiled mollusc shell. The term umbilicus is often used in descriptions of gastropod shells, i.e. it is a feature present on the ventral (or under) side of many (but not all) snail shells, including some species of sea snails, land snails, and freshwater snails. The word is also applied to the depressed central area on the planispiral coiled shells of ''Nautilus'' species and fossil ammonites. (These are not gastropods, but shelled cephalopods.) In gastropods The spirally coiled whorls of gastropod shells frequently connect to each other by their inner sides, during the natural course of its formation. This results in a more or less solid central axial pillar, known as the columella. The more intimate the contact between the concave side of the whorls is, the more solid the columella becomes. On the other hand, if this connection is less intense, a hollow space inside the whorls may re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isonema (gastropod)
''Isonema'' is a genus of plant in the family Apocynaceae first described as a genus in 1810. It is native to Africa. ;Species * ''Isonema buchholzii'' Engl. - Nigeria, Cameroon * ''Isonema infundibuliflorum'' Stapf - Cameroon, Gabon, Zaire * ''Isonema smeathmannii ''Isonema'' is a genus of plant in the family Apocynaceae first described as a genus in 1810. It is native to Africa. ;Species * ''Isonema buchholzii'' Engl. - Nigeria, Cameroon * ''Isonema infundibuliflorum ''Isonema'' is a genus of plant ...'' Roem. & Schult. - W Africa (Ghana, Guinea, Guinea-Bissau, Ivory Coast, Liberia, Senegal, Sierra Leone) References Apocynaceae genera {{Apocynaceae-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
