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Circumocular suture and visual surface of “Cedaria” woosteri (Trilobita, Late Cambrian) from the Eau Claire Formation, Wisconsin

Published online by Cambridge University Press:  20 May 2016

Nigel C. Hughes ,
Gerald O. Gunderson  and
Michael J. Weedon
Nigel C. Hughes
Affiliation:
Geier Collections and Research Center, Cincinnati Museum Center, 1720 Gilbert Avenue
Gerald O. Gunderson
Affiliation:
Cincinnati, Ohio 45202, 6413 Elmwood Avenue, Middleton, Wisconsin 53562
Michael J. Weedon
Affiliation:
Department of Palaeontology, Natural History Museum, Cromwell Road, London, SW7 5BD, U.K.
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Abstract

Rare specimens of the Late Cambrian primitive libristomate trilobite “Cedaria” woosteri from the Eau Claire Formation of north-central Wisconsin preserve an unusual and new ocular suture, and the impressions of lens facets. The suture is circumocular, but loops abaxially onto the ocular platform. The portion of the ocular platform that is enclosed by this suture and is fused with the visual surface is here termed the “ocular plate”. The size and arrangement of the lens facets show that “C.” woosteri possessed a holochroal eye, typical of that known in other Cambrian libristomate trilobites. This nearshore assemblage, while low in diversity, contains a disparate array of trilobite morphotypes.

Type
Research Article
Information
Journal of Paleontology , Volume 71 , Issue 1 , January 1997 , pp. 103 - 107
Copyright
Copyright © The Paleontological Society 

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