Fearnhead, Fiona E. and Donovan, S.K. (2007) A robust crinoid from the Llandovery (Lower Silurian) of Norbury, Shropshire: systematics, palaeoecology and taphonomy. Proceedings of the Geologists' Association 118 (4), 339 - 345. ISSN 0016-7878.Full text not available from this repository.
Crinoids remain poorly known from the Llandovery of the British Isles despite disarticulated columnals being locally common. Cyclocyclicus (col.) geoffnewalli sp. nov. is based on common columnals and rarer pluricolumnals from Norbury quarry, south Shropshire (upper Llandovery, Telychian, Pentamerus Beds). It most probably represents a camerate or perhaps a cladid. The radial symplectial articulation of this species extends to the edge of the jugulum, claustra are sloping, there is no areola and the heteromorphic column, N212, has nodals with convex latera. Radice (=holdfast) ossicles are gracile, of similar morphology to columnals, but small and low. Cyclocyclicus (col.) geoffnewalli is a common component of the Pentamerus community at Norbury, where it dominated the sessile benthos with Pentamerus. Constrictions of the axial canal suggest that it contained only a limited amount of soft tissues whatever the diameter. Similar columnals are known from elsewhere in the Telychian of the Welsh Borderland, suggesting that C. (col.) geoffnewalli may have been distributed broadly in the shelly benthos of this region.
|Keyword(s) / Subject(s):||Silurian, Llandovery, Shropshire, Crinoidea, columnals|
|School or Research Centre:||Birkbeck Schools and Research Centres > School of Science > Earth Sciences|
|Date Deposited:||09 Aug 2011 14:22|
|Last Modified:||17 Apr 2013 12:21|
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