A new Silurian ophiuroid from the west of Ireland

Blake, Daniel B.; Donovan, Stephen K.; Harper, David A.T.

doi:10.3318/ijes.2017.35.57

A new Silurian ophiuroid from the west of Ireland

Blake, Daniel B.; Donovan, Stephen K.; Harper, David A.T.

Authors

Daniel B. Blake

Stephen K. Donovan

Professor David Harper david.harper@durham.ac.uk
Emeritus Professor

Abstract

Silurian echinoderms from Ireland are poorly known; hitherto, only three nominal species have been described, all crinoids and all from the Telychian (Upper Llandovery, Lower Silurian) Kilbride Formation in County Galway. A new species from this formation, Crepidosoma doylei, is the first recorded Irish Silurian ophiuroid (brittle star). The new species is described from five articulated specimens; all are mouldic and none retains a counterpart. The disc and immediately adjacent arm lateral ossicles of the new species differ in shape from those of the type species in that these ossicles are comparatively flat rather than angular or ridged, and the series is marked by a well-defined channelway that appears to have extended from within the disc for the full length of the free arm. Ambital framework ossicles are smooth, and not S- or Z-shaped and ridged as in the type species. The new specimens of C. doylei were recovered from distal storm deposits that are thought to be deep-water equivalents of Benthic Assemblage Zone 5 (Clorinda Community).

Citation

Blake, D. B., Donovan, S. K., & Harper, D. A. (2017). A new Silurian ophiuroid from the west of Ireland. Irish Journal of Earth Sciences, 35, 57-66. https://doi.org/10.3318/ijes.2017.35.57

Journal Article Type	Article
Acceptance Date	Oct 10, 2017
Online Publication Date	Nov 20, 2017
Publication Date	Nov 20, 2017
Deposit Date	Nov 16, 2017
Publicly Available Date	Nov 30, 2017
Journal	Irish journal of earth sciences.
Print ISSN	0790-1763
Electronic ISSN	2009-0064
Publisher	Royal Irish Academy
Peer Reviewed	Peer Reviewed
Volume	35
Pages	57-66
DOI	https://doi.org/10.3318/ijes.2017.35.57