Hostname: page-component-848d4c4894-ttngx Total loading time: 0 Render date: 2024-05-21T08:53:15.721Z Has data issue: false hasContentIssue false

Macroscenella (Mollusca) from the Middle Ordovician of Wisconsin—a reinterpretation and reassignment

Published online by Cambridge University Press:  20 May 2016

Ellis L. Yochelson*
Affiliation:
Department of Paleobiology, National Museum of Natural History, Washington, D.C. 20560 and United States Geological Survey (retired)

Abstract

Description of two new specimens of Macroscenella superba (Billings) provides additional data on this rare, poorly known Paleozoic genus. Macroscenella was considered first to be a gastropod, then a monoplacophoran, and finally a coelenterate. Chondrophorine affinities for this form cannot be totally ruled out, but the new specimens increase the probability that it is a mollusk. If so, Macroscenella is more likely a patellacean gastropod than a member of any other group of the Mollusca, though evidence for placement within the Mollusca is equivocal; the interior of the specimens is not exposed and musculature is unknown. If the integument was a shell, it was thin.

Type
Research Article
Copyright
Copyright © The Paleontological Society 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Billings, E. 1865. Palaeozoic Fossils. Geology of Canada, Volume 1. Geological Survey of Canada, 426 p.Google Scholar
Horny, R. 1963. Lower Paleozoic Monoplacophora and patellid Gastropoda (Mollusca) of Bohemia. Ustredni Ustav Geologicky, Sbornik, 38:783.Google Scholar
Knight, J. B. 1952. Primitive fossil gastropods and their bearing on gastropod classification. Smithsonian Miscellaneous Collections, 117(13), 56 p.Google Scholar
Knight, J. B., and Yochelson, E. L. 1960. Monoplacophora, p. 177184. In Moore, R. C. (ed.), Treatise on Invertebrate Paleontology, Volume I, Mollusca 1. Geological Society of America and University of Kansas Press, Lawrence.Google Scholar
Landing, E., and Narbonne, G. M. 1992. Scenella and “A chondrophorine (medusoid hydrozoan) from the basal Cambrian (Placentian) of Newfoundland.” Journal of Paleontology, 60:338.Google Scholar
Oliver, W. A. Jr. 1984. Conchopeltis: its affinities and significance. Palaeontographica Americana, 54:141147.Google Scholar
Peel, J. S. 1991a. Functional morphology of the class Helcionellacea nov., and the early evolution of the Mollusca, p. 157179. In Simonetta, A. M. and Morris, Simon Conway (eds.), The Early Evolution of Metazoa and the Significance of Problematic Taxa. Cambridge University Press, Oxford.Google Scholar
Peel, J. S. 1991b. Functional morphology, evolution and systematics of early Palaeozoic univalved molluscs. Grønlands Geologiske Undersøgelse, Bulletin 161, 116 p.Google Scholar
Ulrich, E. O. and Scofield, W. H. 1897. The Lower Silurian Gastropoda of Minnesota. Minnesota Geological Survey, Volume 3(2):8131081.Google Scholar
Wenz, W. 1940. Ursprang und frühe Stammergeschichte der Gastropoden: Archiv für Molluskenkunde, 72:110.Google Scholar
Wilson, A. E. 1951. Gastropoda and Conularida of the Ottawa Formation of the Ottawa-St. Lawrence lowland. Geological Survey of Canada, Bulletin 17, 149 p.Google Scholar
Yochelson, E. L. 1984. North American Middle Ordovician Scenella and Macroscenella as possible chondrophorine coelenterates. Palaeontolographica Americana, 54:148153.Google Scholar
Yochelson, E. L. 1988. A new genus of Patellacea (Gastropoda) from the Middle Ordovician of Utah: the oldest known example of the superfamily. New Mexico Bureau of Mines and Mineral Resources, Memoir 44:195200.Google Scholar
Yochelson, E. L., and Gil Cid, D. 1984. Reevaluation of the systematic position of Scenella. Lethaia, 17:331340.Google Scholar
Yochelson, E. L., and Stanley, G. D. Jr. 1981. An early Ordovician patelliform gastropod, Palaeolophacmaea, reinterpreted as a coelenterate. Lethaia, 14:323330.Google Scholar