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Description and ecology of a new Middle Ordovician (Llanvirn) odontopleurid trilobite from the Builth Inlier of Mid-Wales, with a review of the genus Meadowtownella

Published online by Cambridge University Press:  09 August 2011

TIM M. CONWAY*
Affiliation:
Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge, United Kingdom
JOSEPH P. BOTTING
Affiliation:
Nanjing Institute of Geology and Palaeontology, No. 39 Beijing Road, Nanjing, China
*
Author for correspondence: conway.tm@gmail.com

Abstract

A new odontopleurid trilobite, Meadowtownella serrata, is described from a new Llanvirnian (Darriwilian; Didymograptus murchisoni Biozone) locality in the Builth Inlier, Mid-Wales. This unusually spinose species displays a remarkable array of pygidial spines and extends the stratigraphic range of the genus back into the Abereiddian. Benthic faunas are rare in the predominantly ‘anoxic’ D. murchisoni Biozone of the Welsh Basin, and these beds are an unusual habitat for odontopleurids. Environmental analyses (framboidal pyrite and associated total organic carbon) in this study, together with the distribution of benthic faunas (described and figured) in the section, indicate a likely oxic water column and episodically oxic bottom waters. A new diagnosis for Meadowtownella is presented with a review of the genus, as a clarification of previous work. The greater spinosity of earlier members of the lineage may reflect either changing environmental preferences, or the derivation of Meadowtownella from an original more spinose lineage.

Type
Original Articles
Copyright
Copyright © Cambridge University Press 2011

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