Systematic revision of the Cynodontinae (Teleostei: Ostariophysi: Characiformes).
Item
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Title
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Systematic revision of the Cynodontinae (Teleostei: Ostariophysi: Characiformes).
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Identifier
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AAI9808016
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identifier
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9808016
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Creator
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Toledo-Piza, Monica S.
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Contributor
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Adviser: Melanie L. J. Stiassny
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Date
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1997
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Language
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English
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Publisher
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City University of New York.
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Subject
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Biology, Zoology
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Abstract
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Osteological features of cynodontines and other characiforms were examined in an attempt to investigate monophyly of the Cynodontinae and relationships among their species. A number of derived characters corroborated the monophyly of the Cynodontinae. Two equally most parsimonious hypotheses account for relationships among cynodontines, differing in the placement of Rhaphiodon vulpinus. Under one hypothesis Rhaphiodon vulpinus is the sister group to the genus Cynodon, and together they are the sister group to Hydrolycus. Under the alternative hypothesis, Rhaphiodon vulpinus is the sister group to the clade formed by Hydrolycus n. sp. 2, H. armatus, and H. scomberoides. Hydrolycus n. sp. 1 is the sister group to the latter clade. Hydrolycus n. sp. 1 is conservatively included within Hydrolycus.;There are two species in the genus Cynodon Agassiz, 1829. Cynodon gibbus Agassiz, 1829, occurs in the Rio Amazonas and Rio Orinoco basins, the Rupununi River in Guyana, the Rio Tocantins drainage and the Rio Pindare system, Maranhao, Brazil. Cynodon n. sp. 1 occurs in the Rio Amazonas, and in the Essequibo and Demerara Rivers in Guyana.;There are four species in Hydrolycus Muller and Troschel, 1844. Hydrolycus scomberoides (Cuvier, 1819) occurs in the Rio Amazonas and its tributaries. Cynodon pectoralis Gunther, 1866 is a synonym of Hydrolycus scomberoides. Hydrolycus armatus (Schomburgk, 1841) is a valid species and occurs in the central and eastern portions of the Rio Amazonas basin, the Rios Tocantins and Rio Capim, the Essequibo River in Guyana, and Rio Orinoco basin. Hydrolycus n. sp. 2 occurs in sympatry with Hydrolycus armatus in most of the distributional range of the latter species in the Rios Amazonas, Tocantins, and Capim basins and Essequibo River in Guyana. It occurs also in the upper portions of the Rio Orinoco basin. Hydrolycus n. sp. 1 is restricted to the Rio Negro and upper Rio Orinoco basin.;Rhaphiodon Agassiz, 1829 is monotypic with R. vulpinus being the most widely distributed cynodontine. It occurs in the Rios Amazonas, Tocantins, Capim, and Rio Orinoco basins; Rupununi River in Guyana, Rio Parana-Paraguay and Rio Uruguay systems.
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Type
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dissertation
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Source
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PQT Legacy CUNY.xlsx
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degree
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Ph.D.
