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Uranoceratidae
The Uranoceratidae is a family of Silurian barrandeoceroids that tend to become uncoiled with age and in which siphuncle segments tend to be expanded into the camerae.Flower, R.H. & Kummel, B. 1950. A Classification of the Nautiloidea. Journal of Paleontology vol 24, no.5, pp604–616, Sept 1950. Description Shells of uranoceratids are gyroconic. Early stages of a few species are annulated. Later stages of all are smooth or faintly striated or cancellated.Sweet, Walter C, 1964. Nautiloidea - Barrandeocerida, in Treatise on Invertebrate Paleontology, Part K, Geol Soc of America, Teichert & Moore(eds). In many, septal In biology, a septum (Latin for ''something that encloses''; plural septa) is a wall, dividing a cavity or structure into smaller ones. A cavity or structure divided in this way may be referred to as septate. Examples Human anatomy * Interatri ... necks are straight, but in others recumbent on one side or the other. Connecting rings are thin. Derivation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jolietoceras
''Jolietoceras'' is a compressed, annulate, lituiconic nautiloid included in the derived Tarphycerid family, Uranoceratidae The Uranoceratidae is a family of Silurian barrandeoceroids that tend to become uncoiled with age and in which siphuncle segments tend to be expanded into the camerae.Flower, R.H. & Kummel, B. 1950. A Classification of the Nautiloidea. Journal .... The shell is gyroconic in the early stage, becoming straight and more rapidly expanded in the later. sutures are straight and transverse. Surface annuli slope strongly to the rear, dorso-ventrally, in the early gyroconic stage but a lacking in the later straight segment. ''Jolietoceras'' comes from the Middle Silurian of the United States (Illinois, Wisconsin). The Uranoceratidae, ''including Jolietoceras'', were one included in the Barrandeocerida (Sweet, 1964), which has since been incorporated into the Tarphycerida. References * Sweet, W. C. 1964 Nautiloidea- Barrandeocerida. Treatise on Inverteb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Barrandeoceroids
The Barrandeocerina comprise a suborder of Early Paleozoic nautiloid cephalopods, primitively coiled but later forms may be cyrtoconic, gyroconic, torticonic, and even breviconic, all having empty siphuncles with thin connecting rings. The Barrandeocerina were originally defined as a separate order by Rousseau Flower (Flower and Kummel, 1950), but since then have been united within the Tarphycerida as a suborder (Teichert 1988). Derivation is from the Tarphyceratidae. In early forms the siphuncle is central or subcentral, orthochoanitic (septal necks short and straight), and thin, with tubular segments. Later forms include those with cyrtochoanitic septal necks (curved outward) and segments that may be slightly to strongly expanded into the chambers. Taxonomy Six families are included in the Barrandeocerina, (ex Barrandeocerida). :Barrandeoceratidae M Ord-M Dev :Plectoceratidae M-U Ord :Apsidoceratidae M-U Ord :Uranoceratidae U Ord-M Sil :Lechritrochoceratidae M-U Sil :N ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cliftonoceras
''Cliftonoceras'' is a genus of barrandeoceroid type tarphycerids from the Uranoceratidae characterized by a smooth gyroconic shell with a rounded dorsum and flattened venter, and by a subvental siphuncle composed of thin connecting rings and necks that are straight ventrally, recumbent dorsally. ''Cliftonoceras'' has been found in Middle Silurian age sediments in Tennessee and Indiana Indiana () is a U.S. state in the Midwestern United States. It is the 38th-largest by area and the 17th-most populous of the 50 States. Its capital and largest city is Indianapolis. Indiana was admitted to the United States as the 19th s .... The type species is ''C. quadratum''. References * Sweet, Walter C. 1964. Nautiloidea-Barrandeocerida. Treatise on Invertebrate Paleontology, Part K. Geol Soc of America and Univ Kansas Press. Prehistoric nautiloid genera {{paleo-nautiloid-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cumingsoceras
''Cummingsoceras'' is a genus of barrandeoceroids within the Tarphycerida, included in the family Uranoceratidae. Its shell is a rapidly expanding gyrocone of about 1.5 narrowly separated whorls. The surface is faintly cancellated by slight longitudinal lines that cross growth lines which define a deep hyponmic sinus. The siphuncle is small, subcentral, and with recumbent necks. ''Cummingsoceras'' is known from the middle Silurian of Indiana and Illinois Illinois ( ) is a U.S. state, state in the Midwestern United States, Midwestern United States. Its largest metropolitan areas include the Chicago metropolitan area, and the Metro East section, of Greater St. Louis. Other smaller metropolita .... References * Sweet, Walter C. 1964. Nautiloidea-Barrandeocerida. Treatise on Invertebrate Paleontology, Part K. Geol Soc of America and Univ Kansas Press. Prehistoric nautiloid genera {{paleo-nautiloid-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Uranoceras
''Uranoceras'' is a barrandeocerid genus from the Middle Silurian belonging to the family Uranoceratidae, characterized by its loosely coiled, gyroconic shell of 1.5 to 2 subquadrate whorls. The shell of ''Uranoceras'' is typically smooth but may have growth lines that form a hyponomic sinus on the venter. The Siphuncle is large, displaced slightly ventral from the center. Septal necks are straight; connecting rings cylindrical, thin, and strongly contracted where they meet the necks. ''Uranoceras'' has been found in Indiana, Illinois, and Wisconsin in the United States; Anticosti Island in Canada; and in both central and northern Europe. See also * List of nautiloids References * Sweet, Walter C. 1964. Nautiloidea-Barrandeocerida. Treatise on Invertebrate Paleontology The ''Treatise on Invertebrate Paleontology'' (or ''TIP'') published by the Geological Society of America and the University of Kansas Press, is a definitive multi-authored work of some 50 volumes, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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] |
Recumbence
Lyingalso called recumbency, prostration, or decubitus in medicine ()is a type of human position in which the body is more or less horizontal and supported along its length by the surface underneath. Lying is the most common position while being immobilized (e.g. in bedrest), while sleeping, or while being struck by injury or disease. Positions When lying, the body may assume a great variety of shapes and positions. The following are the basic recognized ones. * Supine: lying on the back on the ground with the face up. * Prone: lying on the chest with the face down ("lying down" or "going prone"). See also "Prostration". * Lying on either side, with the body straight or bent/curled forward or backward. ** The fetal position is lying or sitting curled, with limbs close to the torso and the head close to the knees. ** The recovery position (coma position), one of a series of variations on a lateral recumbent or three-quarters prone position of the body, into which an unconsc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prehistoric Nautiloid 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] |
Cancellated
A bone is a rigid organ that constitutes part of the skeleton in most vertebrate animals. Bones protect the various other organs of the body, produce red and white blood cells, store minerals, provide structure and support for the body, and enable mobility. Bones come in a variety of shapes and sizes and have complex internal and external structures. They are lightweight yet strong and hard and serve multiple functions. Bone tissue (osseous tissue), which is also called bone in the uncountable sense of that word, is hard tissue, a type of specialized connective tissue. It has a honeycomb-like matrix internally, which helps to give the bone rigidity. Bone tissue is made up of different types of bone cells. Osteoblasts and osteocytes are involved in the formation and mineralization of bone; osteoclasts are involved in the resorption of bone tissue. Modified (flattened) osteoblasts become the lining cells that form a protective layer on the bone surface. The mineralized ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
