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Morphometric study of the platform elements of Amydrotaxis praejohnsoni n. sp. (Lower Devonian, conodonts, Nevada)

Published online by Cambridge University Press:  19 May 2016

Michael A. Murphy  and
Kathleen B. Springer
Michael A. Murphy
Affiliation:
Department of Earth Sciences, University of California, Riverside 92521
Kathleen B. Springer
Affiliation:
Department of Earth Sciences, University of California, Riverside 92521
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Abstract

The platform element of the conodont Amydrotaxis praejohnsoni n. sp. shows statistically significant morphological changes from the base to the top of the delta Zone (Lower Devonian). The changes occur particularly in mean denticle number, height and character of the anterior denticles, and shape of the basal cavity. The earliest forms have fewer denticles ( = 7.1), an enlarged, high anterior denticle, and a broadly flared posterior basal cavity, whereas late forms have more denticles ( = 9.4), equal-sized anterior denticles, and a narrow posterior basal cavity. There is no stasis phase in the species history, but rather a mosaic pattern in which the observed changes in the character states are seemingly independent of each other and proceed at variable rates.

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Type
Research Article
Information
Journal of Paleontology , Volume 63 , Issue 3 , May 1989 , pp. 349 - 355
Copyright
Copyright © The Paleontological Society 

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