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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] |
Medlicottioidea
The Medlicottioidea is one of two superfamilies that make up the Prolecanitida, the other being the Prolecanitoidea. The Medlicottioidea are recognized by their discoidal to thinly lenticular, and involute shells with small umbilici; flat, often grooved venters, and variably complex sutures. Medlicottiacean shells are often more ornamented and may sport ventrolateral nodes or ribs. The Medlicottioidea combines two related families, the ancestral Pronoritidae, descended from the Prolecanitidae in the Upper Mississippian and the derived Medlicottiidae which first appeared in the Lower Pennsylvanian. A third family, the Sageceratidae, considered to be derived from the Medlicottiidae, is included in the Ceratitida in more recent classifications. The Medlicottiaceae have become known by the alternative Medlicottiodea, following the recent ruling by the ICZN The International Code of Zoological Nomenclature (ICZN) is a widely accepted convention in zoology that rules the formal ... [...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] |
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] |
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] |
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] |
Ammonite Families
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 near Pompe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ceratitida
Ceratitida is an order that contains almost all ammonoid cephalopod genera from the Triassic as well as ancestral forms from the Upper Permian, the exception being the phylloceratids which gave rise to the great diversity of post Triassic ammonites. Ceratitids overwhelmingly produced planospirally coiled discoidal shells that may be evolute with inner whorls exposed or involute with only the outer whorl showing. In a few later forms the shell became subglobular, in others, trochoidal or uncoiled. Sutures are typically ceratitic, with smooth saddles and serrate or digitized lobes. In a few the sutures are goniatitic while in others they are ammonitic. Taxonomy * Ceratitida **Ceratitoidea ** Choristoceratoidea **Clydonitoidea **Danubitoidea **Dinaritoidea ** Lobitoidea ** Meekoceratoidea ** Megaphyllitoidea ** Nathorstitoidea **Noritoidea ** Otoceratoidea ** Pinacoceratoidea **Ptychitoidea ** Sageceratoidea **Tropitoidea ** Xenodiscoidea Only eight superfamilies are sho ... [...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] |
