Paradoxidid trilobites from a mid-Cambrian (Series 3, stage 5) limestone concretion from Jämtland, central Sweden

 

Authors: Rushton AWA, Weidner T, Ebbestad JOR

Published in: Bulletin of Geosciences, volume 91, issue 3; pages: 515 - 552; Received 29 March 2016; Accepted in revised form 30 June 2016; Online 11 October 2016

Keywords: Cambrian, stage 5, Jämtland, Sweden, Eccaparadoxides, Hydrocephalus, morphology, taxonomy,

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Abstract

This paper describes the morphology and discusses the taxonomy of the paradoxidid trilobites present in the moult ensemble described by Ebbestad et al. (2013) from a huge limestone concretion of the Alum Shale Formation collected at Östnar, Jämtland. Two species, both represented by numerous but small complete holaspid specimens are described as new: Eccaparadoxides? thorslundi sp. nov. is distinctive, but its generic position is considered doubtful; Hydrocephalus spinulosus is similar to H. vikensis Rushton&Weidner, 2007 (also present as a rarity in the moult ensemble) and is partly distinguished from it by characters of the thorax. Also illustrated are a few specimens that have been collected at various localities between Hackas and Brunflo. They appear to represent individuals of some of the species in the moult ensemble and are about twice the size of their type specimens.

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