Orthida

picture info	Orthida Orthida is an extinct order of brachiopods which appeared during the Early Cambrian period and became very diverse by the Ordovician, living in shallow-shelf seas. Orthids are the oldest member of the subphylum Rhynchonelliformea, and is the order from which all other brachiopods of this group stem. Physically they are usually strophic, with well-developed interareas. They also commonly have radiating ribs, sulcus, and fold structures. Typically one valve, often the brachial valve, is flatter than the other. The interior structure of the brachial valves are usually simple. In shape they are sub-circular to elliptical, with typically biconvex valves. There is some debate over the forms that first appeared of this order as to how they should be classified. However, they began to differentiate themselves by the late Early Cambrian period, and by the late Cambrian period had diversified into numerous varieties and reach 2 to 5 cm in width. Specimens from the late Cambria ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Plaesiomyidae Plaesiomyidae is a family of extinct lamp shells belonging to the order Orthida. Fossil record Fossils of Plaesiomyidae are found in marine strata from the Ordovician until the 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 Paleozo ... (age range: from 478.6 to 418.7 years ago.). Genera †'' Austinella'' Foerste, 1909 †'' Bokotorthis'' Popov ''et al.'', 2000 †'' Campylorthis'' Ulrich and Copper, 1942 †'' Chaulistomella'' †'' Dinorthis'' Hall and Clarke, 1892 †'' Evenkina'' †'' Madiorthis'' Zuykov and Harper, 2008 †'' Metorthis'' †'' Multicostella'' †'' Plaesiomys'' Hall and Clarke, 1892 †'' Retrorsirostra'' Schuchert and Cooper, 1932 †'' Valcourea'' References {{Taxonbar, from=Q18574617 Prehistoric protostome families Prehistoric b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
picture info	Brachiopod Brachiopods (), phylum Brachiopoda, are a phylum of trochozoan animals that have hard "valves" (shells) on the upper and lower surfaces, unlike the left and right arrangement in bivalve molluscs. Brachiopod valves are hinged at the rear end, while the front can be opened for feeding or closed for protection. Two major categories are traditionally recognized, articulate and inarticulate brachiopods. The word "articulate" is used to describe the tooth-and-groove structures of the valve-hinge which is present in the articulate group, and absent from the inarticulate group. This is the leading diagnostic skeletal feature, by which the two main groups can be readily distinguished as fossils. Articulate brachiopods have toothed hinges and simple, vertically-oriented opening and closing muscles. Conversely, inarticulate brachiopods have weak, untoothed hinges and a more complex system of vertical and oblique (diagonal) muscles used to keep the two valves aligned. In many brachiopods, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Orthidae Orthoidea is a Superfamily (biology), superfamily of Brachiopod, brachiopods containing the families: * Family Orthidae * Family Anomalorthidae * Family Bohemiellidae * Family Glyptorthidae * Family Hesperonomiidae * Family Hesperorthidae * Family Lycophoriidae * Family Nanorthidae * Family Orthidiellidae * Family Plaesiomyidae * Family Poramborthidae * Family Productorthidae * Family Whittardiidae References Rhynchonellata {{Brachiopod-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
picture info	Ordovician The Ordovician ( ) is a geologic period and System (geology), system, the second of six periods of the Paleozoic Era (geology), Era. The Ordovician spans 41.6 million years from the end of the Cambrian Period million years ago (Mya) to the start of the Silurian Period Mya. The Ordovician, named after the Celtic Britons, Welsh tribe of the Ordovices, was defined by Charles Lapworth in 1879 to resolve a dispute between followers of Adam Sedgwick and Roderick Murchison, who were placing the same Rock (geology), rock beds in North Wales in the Cambrian and Silurian systems, respectively. Lapworth recognized that the fossil fauna in the disputed Stratum, strata were different from those of either the Cambrian or the Silurian systems, and placed them in a system of their own. The Ordovician received international approval in 1960 (forty years after Lapworth's death), when it was adopted as an official period of the Paleozoic Era by the International Union of Geological Sciences, Intern ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Orthoidea Orthoidea is a superfamily of brachiopods containing the families: * Family Orthidae * Family Anomalorthidae * Family Bohemiellidae * Family Glyptorthidae * Family Hesperonomiidae * Family Hesperorthidae * Family Lycophoriidae * Family Nanorthidae * Family Orthidiellidae * Family Plaesiomyidae Plaesiomyidae is a family of extinct lamp shells belonging to the order Orthida. Fossil record Fossils of Plaesiomyidae are found in marine strata from the Ordovician The Ordovician ( ) is a geologic period and system, the second of six period ... * Family Poramborthidae * Family Productorthidae * Family Whittardiidae References Rhynchonellata {{Brachiopod-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Plectorthoidea A superfamily of brachiopods containing: * Family Plectorthidae * Family Cremnorthidae * Family Cyclocoeliidae * Family Eoorthidae * Family Euorthisinidae * Family Finkelnburgiidae * Family Giraldiellidae * Family Phragmorthidae * Family Platystrophiidae * Family Ranorthidae * Family Rhactorthidae * Family Tasmanorthidae * Family Wangyuiidae References Rhynchonellata {{Brachiopod-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Botomian Cambrian Stage 4 is the still unnamed fourth stage of the Cambrian and the upper stage of Cambrian Series 2. It follows Cambrian Stage 3 and lies below the Wuliuan. The lower boundary has not been formally defined by the International Commission on Stratigraphy. One proposal is the first appearance of two trilobite genera, ''Olenellus'' or ''Redlichia''. Another proposal is the first appearance of the trilobite species '' Arthricocephalus chauveaui''. Both proposals will set the lower boundary close to million years ago. The upper boundary corresponds to the beginning of the Wuliuan. Naming The International Commission on Stratigraphy The International Commission on Stratigraphy (ICS), sometimes referred to unofficially as the "International Stratigraphic Commission", is a daughter or major subcommittee grade scientific daughter organization that concerns itself with stratigra ... has not named the fourth stage of the Cambrian yet. In the widely used Siberian nomenclature stage ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]