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Hinge grades in the evolution of crassatellacean bivalves as revealed by Permian genera. American Museum novitates ; no. 2328

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dc.contributor.author Boyd, Donald Wilkin. en_US
dc.contributor.author Newell, Norman Dennis, 1909- en_US
dc.date.accessioned 2005-10-06T16:28:50Z
dc.date.available 2005-10-06T16:28:50Z
dc.date.issued 1968 en_US
dc.identifier.uri http://hdl.handle.net/2246/2538
dc.description 52 p. : ill. ; 24 cm. en_US
dc.description Includes bibliographical references (p. 50-52). en_US
dc.description.abstract "The origin and affiliation of the conservative bivalve superfamily Crassatellacea Férussac, 1882 (= Astartacea d'Orbigny, 1844), have been uncertain. Some authors have regarded these mollusks as lucinoids. Others have placed them with the cyrenoids, or in a separate order of the Heterodonta, the 'Astartedonta.' Our discovery of numerous exceptionally well-preserved examples of the Crassatellacea of Permian age in Wyoming clarifies some problems of the early history of the group, showing how, by the acquisition of additional hinge teeth after Permian time, the hinge of living crassatellaceans became modified in separate lines from basically lucinoid to a more advanced hinge grade. Representatives of post-Paleozoic Crassatellidae and Astartidae through convergent evolution resemble one another more closely than do their Paleozoic ancestors, the new subfamilies Oriocrassatellinae and Astartellinae. Members of these Paleozoic subfamilies are sufficiently dissimilar to suggest a diphyletic origin for the Crassatellacea. The Bernard and Munier-Chalmas hinge formula and its implication of dental homologies are discussed, and a simplified, more objective hinge notation based on the Steinmann system is employed. Two new species, Oriocrassatella elongata and Astartella aueri, are described. Examples of hinge transposition of cardinal and anterior lateral teeth, but not the posterior laterals, are recorded in both. This partial transposition of hinge teeth, recorded for the first time in Paleozoic bivalves, indicates that the posterior laterals are genetically independent of the other hinge teeth"--P. [1]-2. en_US
dc.format.extent 8048284 bytes
dc.format.mimetype application/pdf
dc.language eng en_US
dc.language.iso en_US
dc.publisher New York, N.Y. : American Museum of Natural History en_US
dc.relation.ispartofseries American Museum novitates ; no. 2328 en_US
dc.subject.lcc QL1 .A436 no.2328, 1968 en_US
dc.subject.lcsh Oriocrassatella elongata. en_US
dc.subject.lcsh Astartella aueri. en_US
dc.subject.lcsh Crassatellidae, Fossil -- Wyoming -- Wind River Range. en_US
dc.subject.lcsh Mollusks, Fossil -- Wyoming -- Wind River Range. en_US
dc.subject.lcsh Crassatellacea -- Evolution. en_US
dc.subject.lcsh Paleontology -- Permian -- Wyoming -- Wind River Range. en_US
dc.subject.lcsh Paleontology -- Wyoming -- Wind River Range. en_US
dc.title Hinge grades in the evolution of crassatellacean bivalves as revealed by Permian genera. American Museum novitates ; no. 2328 en_US
dc.type text en_US


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  • American Museum Novitates
    Novitates (Latin for "new acquaintances"), published continuously and numbered consecutively since 1921, are short papers that contain descriptions of new forms and reports in zoology, paleontology, and geology. New numbers are published at irregular intervals.

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