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Bisatoceras
''Bisatoceras'' is a late Paleozoic (Upper Mississippian - Upper Pennsylvanian) Ammonoidea, a member of the goniatitid family Bisatoceratidae. ''Bisatoceras'' was named by Miller and Owen in 1937 and has a subdiscoidal shell with a very narrow or closed umbilicus. Whorl height exceeds with at maturity, immature growth stages are globular. Growth lines are usually biconvex, forming ventral and lateral sinuses. Two or three lateral constrictions are formed on each whorl during early growth stages but constrictions are absent at full maturity. The ventral lobe of the suture is double pronged with the median saddle exceeding two thirds the height of the lobe itself. ''Pseudobisatoceras'', named by Maksimova, 1940, is like ''Bisatoceras'' but is distinct in having spiral ornamentation. Its temporal range coincides with the early part of that of ''Bisatoceras''. Miller ''et al'' considered ''Pseudobisatoceras'' a synonym for ''Bisatoceras'' which was included in the family Goniatiti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bisatoceratidae
Bisatoceratidae is a family of Late Paleozoic ammonites now included in the Thalassoceratoidea characterized by thick-discoidal to subglobular, involute shells in which lobes are simple. Some forms have spiral ornamentation. Bisatoceratidae was originally a subfamily of the Goniatitidae as Bisatoceratinae, named by Miller and Furnish, 1957, and introduced in the Treatise on Invertebrate Paleontology, Part L, 1957. Its relation to the Thalassoceratidae Thalassoceratidae a family of late Paleozoic ammonites included in the goniatitid superfamily Thalassoceratoidea along with the Bisatoceratidae. Some eight genera are included, although the specific number and exactly which depends on the part ... is tenuous. References * *Bisatoceratidae iGONIAT6/14/12 * Goniatitida families Thalassoceratoidea {{Goniatitida-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bashkirian
The Bashkirian is in the ICS geologic timescale the lowest stage or oldest age of the Pennsylvanian. The Bashkirian age lasted from to Ma, is preceded by the Serpukhovian and is followed by the Moscovian. The Bashkirian overlaps with the upper part of the Namurian and lower part of the Westphalian stages from regional European stratigraphy. It also overlaps with the North American Morrowan and Atokan stages and the Chinese Luosuan and lower Huashibanian stages. Name and definition The Bashkirian was named after Bashkiria, the then Russian name of the republic of Bashkortostan in the southern Ural Mountains of Russia, home of the Bashkir people. The stage was introduced by Russian stratigrapher Sofia Semikhatova in 1934. The base of the Bashkirian is at the first appearance of conodont species ''Declinognathodus noduliferus''. The top of the stage (the base of the Moscovian) is at the first appearance of the conodonts ''Declinognathodus donetzianus'' or ''Idiognathoides ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Missourian (stage)
The Kasimovian is a geochronology, geochronologic age (geology), age or chronostratigraphy, chronostratigraphic stage (stratigraphy), stage in the International Commission on Stratigraphy, ICS geologic timescale. It is the third stage in the Pennsylvanian (geology), Pennsylvanian (late Carboniferous), lasting from to Megaannum, Ma.; 2004: ''A Geologic Time Scale 2004'', Cambridge University Press. The Kasimovian Stage follows the Moscovian (Carboniferous), Moscovian and is followed by the Gzhelian. The Kasimovian saw an extinction event which occurred around 305 mya, referred to as the Carboniferous Rainforest Collapse. It roughly corresponds to the Missourian in North American geochronology and the Stephanian (stage), Stephanian in western European geochronology. Name and definition The Kasimovian is named after the Russian city of Kasimov. The stage was split from the Moscovian in 1926 by Boris Dan'shin (1891-1941), who gave it the name ''Teguliferina horizon''. The name was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 AD nea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Goniatitidae
Goniatitidae is one of three families included in the ammonoid cephalopod superfamily Goniatitoidea, known from the Lower Mississippian to the Upper Permian The Permian ( ) is a geologic period and stratigraphic system which spans 47 million years from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.9 Mya. It is the last period of the Paleoz .... They have sutures that form 8 lobes and characteristically lack sculpture. The ventral lobe, as for the superfamily, is bifurcated. References * Miller, Furnish, and Schindewolf 1957. Paleozoic Ammonoidea; ''Treatise on Invertebrate Paleontology'', Part L Ammonoidea. Geologocial Society of America and Univ of Kansas Press. GoniatitidaePaleo db 9/07/13 Goniatitida families Goniatitoidea {{Goniatitida-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Goniatitida Genera
Goniatids, informally goniatites, are ammonoid cephalopods that form the order Goniatitida, derived from the more primitive Agoniatitida during the Middle Devonian some 390 million years ago (around Eifelian stage). Goniatites (goniatitids) survived the Late Devonian extinction to flourish during the Carboniferous and Permian only to become extinct at the end of the Permian some 139 million years later. Morphology All goniatites possessed an external shell, which is divided internally into chambers filled with gas giving it buoyancy during the life of the animal. An open chamber at the front of the shell provided living space for the goniatitid animal, with access to open water through a ventral siphuncle. The general morphology and habit of goniatites was probably similar to that of their later relatives the ammonites, being free swimming and possessing a head with two well developed eyes and arms (or tentacles). Goniatite shells are small to medium in size, almost always l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
