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Evolution of tetrapods

The evolution of tetrapods began about 400 million years ago in the Devonian Period with the earliest tetrapods evolved from lobe-finned fishes. Tetrapods are categorized as animals in the biological superclass Tetrapoda, which includes all living and extinct amphibians, reptiles and mammals. While most species today are terrestrial, little evidence supports the idea that any of the earliest tetrapods could move about on land, as their limbs could not have held their midsections off the ground and the known trackways do not indicate they dragged their bellies around; the tracks were made by animals walking along the bottoms of shallow bodies of water. The specific aquatic ancestors of the tetrapods, the process by which land colonization occurred, remain unclear, are areas of active research and debate among palaeontologists at present. Most amphibians today remain semiaquatic, living the first stage of their lives as fish-like tadpoles. Several groups of tetrapods, such as the snakes and cetaceans, have lost all of their limbs.

In addition, many tetrapods have returned to aquatic or aquatic lives throughout the history of the group. The first returns to an aquatic lifestyle may have occurred as early as the Carboniferous Period whereas other returns occurred as as the Cenozoic, as in cetaceans and several modern amphibians; the change from a body plan for breathing and navigating in water to a body plan enabling the animal to move on land is one of the most profound evolutionary changes known. It is one of the best understood thanks to a number of significant transitional fossil finds in the late 20th century combined with improved phylogenetic analysis; the Devonian period is traditionally known as the "Age of Fish", marking the diversification of numerous extinct and modern major fish groups. Among them were the early bony fishes, who diversified and spread in freshwater and brackish environments at the beginning of the period; the early types resembled their cartilaginous ancestors in many features of their anatomy, including a shark-like tailfin, spiral gut, large pectoral fins stiffened in front by skeletal elements and a unossified axial skeleton.

They did, have certain traits separating them from cartilaginous fishes, traits that would become pivotal in the evolution of terrestrial forms. With the exception of a pair of spiracles, the gills did not open singly to the exterior as they do in sharks; the cleithrum bone, forming the posterior margin of the gill chamber functioned as anchoring for the pectoral fins. The cartilaginous fishes do not have such an anchoring for the pectoral fins; this allowed for a movable joint at the base of the fins in the early bony fishes, would function in a weight bearing structure in tetrapods. As part of the overall armour of rhomboid cosmin scales, the skull had a full cover of dermal bone, constituting a skull roof over the otherwise shark-like cartilaginous inner cranium, they had a pair of ventral paired lungs, a feature lacking in sharks and rays. It was assumed that fishes to a large degree evolved around reefs, but since their origin about 480 million years ago, they lived in near-shore environments like intertidal areas or permanently shallow lagoons and didn't start to proliferate into other biotopes before 60 million years later.

A few adapted to deeper water, while solid and built forms stayed where they were or migrated into freshwater. The increase of primary productivity on land during the late Devonian changed the freshwater ecosystems; when nutrients from plants were released into lakes and rivers, they were absorbed by microorganisms which in turn was eaten by invertebrates, which served as food for vertebrates. Some fish became detritivores. Early tetrapods evolved a tolerance to environments which varied in salinity, such as estuaries or deltas; the lung/swim bladder originated as an outgrowth of the gut, forming a gas-filled bladder above the digestive system. In its primitive form, the air bladder was open to the alimentary canal, a condition called physostome and still found in many fish; the primary function is not certain. One consideration is buoyancy; the heavy scale armour of the early bony fishes would weigh the animals down. In cartilaginous fishes, lacking a swim bladder, the open sea sharks need to swim to avoid sinking into the depths, the pectoral fins providing lift.

Another factor is oxygen consumption. Ambient oxygen was low in the early Devonian about half of modern values. Per unit volume, there is much more oxygen in air than in water, vertebrates are active animals with a high energy requirement compared to invertebrates of similar sizes; the Devonian saw increasing oxygen levels which opened up new ecological niches by allowing groups able to exploit the additional oxygen to develop into active, large-bodied animals. In tropical swampland habitats, atmospheric oxygen is much more stable, may have prompted a reliance of lungs rather than gills for primary oxygen uptake. In the end, both buoyancy and breathing may have been important, some modern physostome fishes do indeed use their bladders for both. To function in gas exchange, lungs require a blood supply. In cartilaginous fishes and teleosts, the heart lies low in the body and pumps blood forward through the ventral aorta, which splits up in a series of paired aortic arches, each corresponding to a gill arch.

The aortic arches merge above the gills to fo

Wendy J. Fox

Wendy J. Fox is an American author born in Washington, she is most known for winning Press 53’s inaugural short-fiction competition with her collection “The Seven Stages of Anger and Other Stories.” Fox has published short stories in the ZYZZYVA, Tampa Review, The Pinch, Washington Square Review, among others. In 2015, Fox was a finalist for the Colorado Book Awards, she was included in 2006’s Tales from the Expat Harem, an anthology of female writers based on the experiences of living in Turkey. Her most recent novel If the Ice Had Held is a Buzzfeed recommended read and a grand prize winner from Santa Fe Writers Project, she resides in Denver, Colorado. Fox was raised in rural eastern Washington state, she attended Wenatchee Valley College. She matriculated from Eastern Washington University. Fox works as a marketer for a technology company, has worked in the information technology sector since 2006; the Seven Stages of Anger and Other Stories Press 53 The Pull of It Underground Voices Official website

Daphnella axis

Daphnella axis, common name the axle pleuratoma, is a species of sea snail, a marine gastropod mollusk in the family Raphitomidae. The shell is contracted at the upper part; the whorls show two keels round the upper part. They are transversely faintly ridged beneath; the aperture is oblong. The sinus, formed between the two keels, is unusually deep; the color of the shell is somewhat indistinctly stained with orange-brown. This marine species occurs off the Philippines, in the Gulf of Oman and in the Gulf of Carpentaria - Queensland, Australia Brazier, J. 1876. A list of the Pleurotomidae collected during the Chevert expedition, with the description of the new species. Proceedings of the Linnean Society of New South Wales 1: 151–162 Powell, A. W. B. 1966. The molluscan families Speightiidae and Turridae, an evaluation of the valid taxa, both Recent and fossil, with list of characteristic species. Bulletin of the Auckland Institute and Museum. Auckland, New Zealand 5: 1–184, pls 1–23 Boettger, O. 1895.

Die marinen Mollusken der Philippinen. IV. Die Pleurotomiden. Nachrichtsblatt der Deutschen Malakozooligischen Gesellschaft 27: 1-20, 41-63 Melvill, J. C. & Standen, R. 1901. The Mollusca of the Persian Gulf, Gulf of Oman, the Arabian Sea, as evidenced through the collections of Mr. F. W. Townsend, 1893-1900. Proceedings of the Zoological Society of London 1901: 327-460 pls xxi-xxiv Hedley, C. 1922. A revision of the Australian Turridae. Records of the Australian Museum 13: 213–359, pls 42–56 Cogger, H. G. in Cogger, H. G. Cameron, E. E. & Cogger, H. M. 1983, "Amphibia and Reptilia", Ed. Walton, D. W. Zoological Catalogue of Australia, vol. 1, pp. 313 pp. Australian Government Publishing Service, Canberra Tucker, J. K.. "Catalog of recent and fossil turrids". Zootaxa. 682: 1–1295

Jim Crockett Promotions

Jim Crockett Promotions Inc. was a family-owned professional wrestling promotion headquartered in Charlotte, North Carolina, United States. Founded in 1931, the promotion emerged as a cornerstone of the National Wrestling Alliance. By the 1980s, Jim Crockett Promotions was, along with the World Wrestling Federation, one of the two largest promotions in the United States; the Crockett family sold a majority interest in the promotion to Turner Broadcasting System in 1988, resulting in the creation of World Championship Wrestling. Jim Crockett was a promoter of live events including professional wrestling, music concerts, minor league baseball, ice hockey. In 1931, he founded Jim Crockett Promotions. Crockett built JCP as a regional promotion centred on the Virginia. Although the business was always called "Jim Crockett Promotions," it used a variety of pseudonyms as brand names for specific TV shows and radio ads, on event tickets, themselves. Among those brand names were the generic standbys, "Championship Wrestling" and "All Star Wrestling".

Crockett joined the National Wrestling Alliance in 1952, his "territory" covered Virginia, North Carolina and South Carolina. The name "Mid-Atlantic Championship Wrestling" became JCP's primary brand name in print and other advertising; the business was incorporated in the 1950s. Jim Crockett died in 1973, he left JCP with his eldest son, Jim Crockett, Jr. taking over as chief executive. Led by the younger Crockett and under the guidance of a new creative force—former wrestler-turned-match-booker George Scott—the promotion moved away from featuring just tag teams, to focusing on singles wrestling. By the early-1970s, JCP had phased-out its multiple weekly television tapings in such cities as Charlotte, North Carolina, South Carolina, High Point, North Carolina, consolidating its production schedule into just one shoot, syndicating the broadcast to several local TV stations throughout the Carolinas and Virginia. In 1981, JCP moved to the WPCQ-TV studios in Charlotte; the local shows hosted by announcers like Big Bill Ward and Charlie Harville gave way to Mid-Atlantic Championship Wrestling.

Mid-Atlantic was hosted by Bob Caudle. Caudle was joined by a rotation of co-hosts, before David Crockett became Caudle's permanent co-host/color commentary man. For a brief period, a secondary show, East Coast Wrestling, was taped at WRAL. In 1975, JCP premiered syndicated "B-show", Wide World Wrestling; the original host of this show was former Georgia Championship Wrestling announcer Ed Capral. Subsequent Wide World/World Wide announcers included Les Thatcher and Sandy Scott, Dr. Tom Miller, it was hosted by the team of Rich Landrum and Johnny Weaver. In 1978, JCP added a short-lived show, The Best of NWA Wrestling, taped at the WCCB studios in Charlotte and featured then-active wrestler Johnny Weaver sitting down with top stars in a "coach's show" format. Rich Landrum and David Crockett appeared on "Best Of". JCP began to expand, running shows in eastern Tennessee, parts of West Virginia, Savannah, Georgia. In the late-1970s and early-1980s, JCP ran regular shows in Dayton, Ohio. Crockett and Scott bought minority shares of Frank Tunney's Toronto-based promotion, Maple Leaf Wrestling.

Mid-Atlantic Championship Wrestling aired on a Buffalo, New York station, enabling the Tunney/Crockett/Scott enterprise to bring a full slate of shows to Ontario and upstate New York. In the 1980s, Crockett, Jr. began consolidating the Southern franchises of the National Wrestling Alliance. Discarding the Mid-Atlantic Championship Wrestling brand, Crockett, Jr. began promoting his events as the National Wrestling Alliance, although his promotion remained distinct from the larger NWA entity. In August 1980, Crockett, Jr. was elected president of the NWA. In 1981, former Georgia Championship Wrestling booker Ole Anderson took over as Mid-Atlantic's booker. In 1981, Anderson booked both GCW simultaneously. In 1982, Crockett partnered with wrestlers Ric Flair and Blackjack Mulligan to start a secondary company out of Knoxville, Tennessee: Southern Championship Wrestling; the promotion featured such stars as Mulligan. The enterprise lasted less than one year, however. By the 1980s, the U. S. pro wrestling industry was undergoing rapid change.

The old, NWA-sanctioned system of separate, regional "territory" promotions was

Tungsten(V) bromide

Tungsten bromide is the inorganic compound with the empirical formula WBr5. The compound consists of bioctahedral structure, with two bridging bromide ligands, so its molecular formula is W2Br10. Tungsten bromide is prepared by treating tungsten powder with bromine in the temperature range 650-1000 °C; the product is contaminated with tungsten hexabromide. According to X-ray diffraction, the structure for tungsten pentabromide consists of an edge-shared bioctahedron. Tungsten bromide is the precursor to other tungsten compounds by reduction reactions. For example, tungsten bromide can be prepared by reduction with tungsten; the WBr4 can be purified by chemical vapor transport. 3 WBr5 + Al → 3 WBr4 + AlBr3Excess tungsten pentabromide and aluminum tribromide are removed by sublimation at 240 °C. Tungsten bromide can be obtained heating the tetrabromide. At 450-500 °C, gaseous pentabromide is evolved leaving yellow-green residue of WBr2. An analogous method can be applied to the synthesis of tungsten chloride.

Because it is easy to reduce tungsten pentahalides, they can be used as alternative synthetic routes to tungsten halide adducts. For example, reaction of WBr5 with pyridine gives WBr42. 2 WBr5 + 7 C5H5N → 2 WBr42 + bipyridine + C5H5NHBr