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Aldanites
''Aldanites'' is an extinct cephalopod genus belonging to the ammonoid order Goniatitida Goniatids, informally goniatites, are Ammonoidea, 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 (goniat .... ''Aldanites'', named by Ruzhencev, 1965, is confined to the Lower Pennsylvanian Period (late Carboniferous) and is included in the Orulganitidae, a family in the Schistoceratacea, a goniatitid superfamily. ''References'' Aldanites-Paleodb* Saunders, Work, and Nikolaeva 1999. Evolution of Complexity in Paleozoic Ammonoid Sutures, supplementary materia* W. M. Furnish, et al. 2009. Treatise on Invertebrate Paleontology, Part L, Revised: Mollusca 4, Volume 2: Carboniferous and Permian Ammonoidea (Goniatitida and Prolecanitida) pp1–258. Goniatitida genera Orulganitidae {{Goniatitida-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pennsylvanian (geology)
The Pennsylvanian ( , also known as Upper Carboniferous or Late Carboniferous) is, in the International Commission on Stratigraphy, ICS geologic timescale, the younger of two period (geology), subperiods (or upper of two system (stratigraphy), subsystems) of the Carboniferous Period. It lasted from roughly . As with most other geochronology, geochronologic units, the stratum, rock beds that define the Pennsylvanian are well identified, but the exact date of the start and end are uncertain by a few hundred thousand years. The Pennsylvanian is named after the U.S. state of Pennsylvania, where the coal-productive beds of this age are widespread. The division between Pennsylvanian and Mississippian (geology), Mississippian comes from North American stratigraphy. In North America, where the early Carboniferous beds are primarily marine limestones, the Pennsylvanian was in the past treated as a full-fledged geologic period between the Mississippian and the Permian. In parts of Europe, ... [...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] |
Goniatitida
Goniatids, informally goniatites, are Ammonoidea, 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 Permian–Triassic extinction event, 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 Ammonitida, ammonites, being free swimming and possessing a head with two well developed eyes and arms (or tentacles). G ... [...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] |
