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Medlicottiinae
The Medlicottiinae is a subfamily of the Medlicottiidae, a family of ammonoid cephalopods included in the Prolecanitida, characterized by having discoidal to thinly lenticular shells with a retuse (grooved) venter and sutures with bifid auxiliary lobes. The Medlicottiinae classically included, by general consensus, the following five genera: ''Artinskia'', ''Eumedlicottia'', ''Medlicottia'', ''Neogeoceras'', and ''Syrdenites''. Of these only ''Artinskia'' and ''Medlicottia'', included in the Medlicottinae in the Treatise (Miller, Furnish, and Schindewolf, 1957) remain in Medlicottinae at present. ''Episageceras'', ''Propinacoceras'', and ''Sicanites'', then included, have become type genera respectively for the Episageceratinae, Propinacoceratinae, and Sicanitinae. ''Artinskia'' is the ancestral form, thought to be derived from ''Uddenoceras'' (Uddenitinae The Uddenitinae a subfamily of the Medlicottiidae, a family of ammonoid cephalopods included in the Prolecanitida. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Episageceratinae
Episageceratinae is a subfamily of the Medlicottiidae, a family of prolecanitid ammonites. The Episageceratinae, proposed by Ruzhencev, 1956, is based on the genus ''Episageceras'' previously included in the subfamily Medlicottiinae and lived during Late Permian and Early Triassic times. So far only three confirmed genera are included: ''Episageceras'', ''Latisageceras'', and ''Nodosageceras''. The type genus, ''Episageceras'', named by Noetling 1904, is defined in the Treatise A treatise is a formal and systematic written discourse on some subject, generally longer and treating it in greater depth than an essay, and more concerned with investigating or exposing the principles of the subject and its conclusions."Treat ... (L74) as like ''Medlicottia'' but with a broader shell and sutures with a smaller second lateral lobe. ''Latisageceras'' and ''Nodosageceras'' named by Ruzhencev 1956 are based on species of ''Episageceras''. J.P Smith, 1932 (USGS PP 167) included ''Ep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Medlicottiidae
Medlicottiidae is a family of ammonoid cephalopods belonging to the Prolecanitida, known from the Upper Carboniferous ( Pennsylvanian) to the Early Triassic. Characteristics Medlicottidae are characterized by discoidal to thinly lenticular shells and sutures with a narrow ventral lobe and a modified first lateral saddle. Taxonomy Subfamilies The Medlicottiide, established by Karpinsky in 1889, is by prevailing current perspective divided into five subfamilies. These are the Episageceratinae, Medlicottiinae, Propinacoceratinae, Sicanitinae, and Uddenitinae. The Artioceratinae and Miklukhoceratinae, sometimes included as well, are junior synonyms respectively for the Sicanitinae and Propinacoceratinae. Previously the Medlicottiidae were divided in part L of the Treatise, 1957, into just two subfamilies, the Uddenitinae introduced by Miller and Furnish in 1940 and the Medlicottinae revised from Karpinsky 1889. Higher taxa The Medlicottiidae are included in the superfamily M ... [...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] |
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 Paleozoic Era; the following Triassic Period belongs to the Mesozoic Era. The concept of the Permian was introduced in 1841 by geologist Sir Roderick Murchison, who named it after the region of Perm in Russia. The Permian witnessed the diversification of the two groups of amniotes, the synapsids and the sauropsids ( reptiles). The world at the time was dominated by the supercontinent Pangaea, which had formed due to the collision of Euramerica and Gondwana during the Carboniferous. Pangaea was surrounded by the superocean Panthalassa. The Carboniferous rainforest collapse left behind vast regions of desert within the continental interior. Amniotes, which could better cope with these drier conditions, rose to dominance in place of their am ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prolecanitida
Prolecanitida is an order of extinct ammonoidea, ammonoid cephalopods with discoidal to thinly lenticular shells with goniatitic or ceratitic sutures and which retained the simple retrochoanitic siphuncle with backward extending septal necks. As typical for ammonoids the siphuncle is along the ventral margin. Prolecanitids form a relatively small and stable order within the Ammonoidea with 43 named genera and about 1250 species, but with a long-ranging lineage of about 108 m.y. stretching from the Lower Carboniferous to the Triassic. Although not as diverse as their Goniatitida, goniatitid contemporaries, the Prolecanatida provided the stock from which all later Mesozoic ammonoids were derived. Evolution and phylogeny The origin of the Prolecanitida may be found in the Prolobitidae which was originally included in the Anarcestida but recently removed to the Goniatitida. Following their inception, the Prolecanitida divided into two lineages, identified by superfamilies; the earlier ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Uddenitinae
The Uddenitinae a subfamily of the Medlicottiidae, a family of ammonoid cephalopods included in the Prolecanitida. The Uddenitinae, proposed by Miller and Furnish, and known from the Pennsylvanian (U Carb) and Lower Permian, are transitional between the ancestral Pronoritidae and the more traditional medlicottiids Morphology Genera of the Uddenitinae have narrow discoidal shells with narrow flat or sometimes grooved venters. Sutures are goniatitic to ceratitic with rounded saddles and slightly pointed to digitate lobes which form a declining series going toward the umbilicus. The ventral lobe is commonly long and narrow, and trifurcated with sharp, simple prongs. Genera The Uddenitinae includes ''Prouddenites'', (ancestral form), ''Uddenites'',(type genus), ''Daixites'', ''Neouddenites'', and ''Uddenoceras''. ''Prouddenites'', named by Miller, 1930, which is found in the Pennsylvanian of the south-central United States and the Urals, has a discoidal shell with a flattened ven ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pennsylvanian First Appearances
Pennsylvanian may refer to: * A person or thing from Pennsylvania * Pennsylvanian (geology), a geological subperiod of the Carboniferous Period * Pennsylvanian (train), ''Pennsylvanian'' (train), an Amtrak train {{disambiguation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cisuralian Extinctions
The Cisuralian is the first series/epoch of the Permian. The Cisuralian was preceded by the Pennsylvanian and followed by the Guadalupian. The Cisuralian Epoch is named after the western slopes of the Ural Mountains in Russia and Kazakhstan and dates between 298.9 ± 0.15 – 272.3 ± 0.5 Mya. The Cisuralian is often synonymous with the informal terms early Permian or lower Permian. It corresponds approximately with the Wolfcampian in southwestern North America. The series saw the appearance of beetles and flies and was a relatively stable warming period of about 21 million years. Name and background The Cisuralian is the first series or epoch of the Permian. The Cisuralian was preceded by the last Pennsylvanian epoch (Gzhelian) and is followed by the Permian Guadalupian Epoch. The name "Cisuralian" was proposed in 1982, and approved by the International Subcommission on Permian Stratigraphy in 1996. The Cisuralian Epoch is named after the western slopes of the Ural Mountain ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
