Life association of shell and operculum of Ceratopea Ulrich, 1911 (Ordovician; Gastropoda)

Ceratopea Ulrich, 1911, from the Lower Ordovician of North America, Greenland, and Scotland, is one of a few gastropod genera that was established on the calcareous operculum and not the shell. The operculum is commonly found disassociated, and for many years the nature of the shell itself was unkno...

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Bibliographic Details
Main Authors: Rohr, David M., Fix, Michael F., Darrough, Guy
Format: Article in Journal/Newspaper
Language:English
Published: Cambridge University Press (CUP) 2004
Subjects:
Online Access:http://dx.doi.org/10.1666/0022-3360(2004)078%3C0218:laosao%3E2.0.co%3B2
https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022336000046308
Description
Summary:Ceratopea Ulrich, 1911, from the Lower Ordovician of North America, Greenland, and Scotland, is one of a few gastropod genera that was established on the calcareous operculum and not the shell. The operculum is commonly found disassociated, and for many years the nature of the shell itself was unknown (Yochelson, 1975). Yochelson and Bridge (1957, pl. 38, figs. 8–9) illustrated an artificial association of C. unguis with its presumed shell made years earlier by Ulrich and Bridge (Yochelson, written commun.). However, the basal part of the shell is not present. Only one life association of the shell and operculum has been previously documented (Yochelson and Wise, 1972), and that shell is incompletely preserved.