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The graptolite nema: problem to all our solutions

Published online by Cambridge University Press:  01 May 2009

R. B. Rickards
R. B. Rickards
Affiliation:
Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EQ, UK
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Abstract

Lack of understanding of the graptolite nema and virgula is probably the main cause of the general failure to arrive at a general mode of life theory for planktonic species. The nema and virgula are shown to be different structures. The nema may have had a rhabdosome rotational function at early growth stages; the primary function of the virgula may have been rhabdosomal rotation, whilst a secondary function was as a stipe growth guide. Rotational function would be inapplicable for pseudovirgulae and in synrhabdosomes.

Type
Rapid Communication
Information
Geological Magazine , Volume 133 , Issue 3 , May 1996 , pp. 343 - 346
Copyright
Copyright © Cambridge University Press 1996

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