Plaesiomyidae

	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]
	Plaesiomys ''Plaesiomys'' is a genus of extinct lamp shells belonging to the family Plaesiomyidae. Fossil record Fossils of ''Plaesiomys'' are found in marine strata of the 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 ... (age range: from 466.0 to 443.7 years ago.) of Canada, China, Europe and United States. Species †''Plaesiomys anticostiensis'' (Shaler, 1865) †''Plaesiomys bellistriatus'' Wang, 1949 †''Plaesiomys carletona'' Twenhofel, 1928 †''Plaesiomys fidelis'' Popov ''et al.'', 2000 †''Plaesiomys iphigenia'' (Billings, 1865) †''Plaesiomys multiplicata'' Bancroft, 1945 †''Plaesiomys porcata'' (McCoy, 1846) †''Plaesiomys proavitus'' Winchell and Schuchert, 1892 †''Plaesiomys rockymontana'' Wilson, 1926 †''Plaesiomys saxbiana'' Oraspold, 1959 � ... [...More Info...] [...Related Items...] OR:* [Wikipedia] [Google] [Baidu]
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]
picture info	Brachiopod Families 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]
picture info	Prehistoric Brachiopods Prehistory, also known as pre-literary history, is the period of human history between the use of the first stone tools by hominins 3.3 million years ago and the beginning of recorded history with the invention of writing systems. The use of symbols, marks, and images appears very early among humans, but the earliest known writing systems appeared 5000 years ago. It took thousands of years for writing systems to be widely adopted, with writing spreading to almost all cultures by the 19th century. The end of prehistory therefore came at very different times in different places, and the term is less often used in discussing societies where prehistory ended relatively recently. In the early Bronze Age, Sumer in Mesopotamia, the Indus Valley Civilisation, and ancient Egypt were the first civilizations to develop their own scripts and to keep historical records, with their neighbors following. Most other civilizations reached the end of prehistory during the following Iron Age. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
picture info	Prehistoric Protostome Families Prehistory, also known as pre-literary history, is the period of human history between the use of the first stone tools by hominins 3.3 million years ago and the beginning of recorded history with the invention of writing systems. The use of symbols, marks, and images appears very early among humans, but the earliest known writing systems appeared 5000 years ago. It took thousands of years for writing systems to be widely adopted, with writing spreading to almost all cultures by the 19th century. The end of prehistory therefore came at very different times in different places, and the term is less often used in discussing societies where prehistory ended relatively recently. In the early Bronze Age, Sumer in Mesopotamia, the Indus Valley Civilisation, and ancient Egypt were the first civilizations to develop their own scripts and to keep historical records, with their neighbors following. Most other civilizations reached the end of prehistory during the following Iron Age. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]