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The Scissurellidae : are they neotenously derived fissurellids? (Archeogastropoda). American Museum novitates ; no. 2567

Show simple item record Batten, Roger Lyman. en_US 2005-10-06T18:21:37Z 2005-10-06T18:21:37Z 1975 en_US
dc.description 29 p. : ill. ; 26 cm. en_US
dc.description Includes bibliographical references (p. 28-29). en_US
dc.description.abstract "Comparative anatomical studies have been made of the families Scissurellidae, Pleurotomariidae, and Fissurellidae. Shared primitive characters such as paired organs and shared derived characters like epipodial tentacles, indicate that the Scissurellidae should be removed from the Pleurotomariacea, despite nearly identical external morphology, and placed in the Fissurellacea. The only available pleurotomariaceans when the scissurellids appeared in early Cenozoic time are the haliotids and the Pleurotomariidae. Neither family has as many shared characters as the scissurellids and the fissurellids. A study of the ultrastructure of the scissurellids further justifies this decision. Ultrastructure normally is quite conservative in major taxa. The pleurotomarians have a complex prismatic-nacreous wall, whereas the scissurellids have a simple prismatic-'type-2 crossed-lamellar' wall. This latter wall type is found in the embryonic stage only of the fissurellids; in adults the wall is crossed-lamellar-crossed-lamellar. The early embryonic stages of the fissurellids are similar or nearly identical with all growth stages in the scissurellids. This observation suggests that the scissurellids might have been neotenously derived from the fissurellids. The scissurellids are remarkably convergent on several genera of the Upper Paleozoic Eotomariidae and the Triassic Temnotropidae in external morphology"--P. [1]. en_US
dc.format.extent 18874031 bytes
dc.format.mimetype application/pdf
dc.language eng en_US
dc.language.iso en_US
dc.publisher New York, Ny.Y. : American Museum of Natural History en_US
dc.relation.ispartofseries American Museum novitates ; no. 2567 en_US
dc.subject.lcc QL1 .A436 no.2567, 1975 en_US
dc.subject.lcsh Scissurellidae. en_US
dc.subject.lcsh Fissurellidae. en_US
dc.subject.lcsh Gastropoda -- Evolution. en_US
dc.subject.lcsh Neoteny. en_US
dc.title The Scissurellidae : are they neotenously derived fissurellids? (Archeogastropoda). American Museum novitates ; no. 2567 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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