Late Ordovician deep-water brachiopod fauna from Raheen, Waterford Harbour, Ireland
Irish Journal of Earth Sciences
2017) 'Late Ordovician deep-water brachiopod fauna from Raheen, Waterford Harbour, Ireland.', Irish journal of earth sciences., 35 . pp. 1-18. The full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that: • a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not
... ll-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders. Please consult the full DRO policy for further details. Abstract The Raheen Formation at Newtown Head in Waterford Harbour is a small isolated section of Ordovician rocks, dominated by volcanics of the Duncannon Group, but with interbedded fossiliferous shales. Although a brachiopod and trilobite dominated fauna has been known since the mid-19 th century only the trilobites and cystoids have been assessed in modern terms. This paper describes the brachiopod fauna for the first time. The assemblage from Raheen is overwhelmingly dominated by the dalmanelloid Onniella, with the small plectambonitoid Sericoidea comprising the second most numerous species; both are represented by new species. This revision has also identified a wide range of other genera, but all in very small numbers. These include an obolid, a paterulid, Paracraniops and Orthisocrania divaricata (M ̒ 'Coy) amongst the non articulated brachiopods. Articulated genera present include the orthoids Nicolella, Ptychopleurella, Sulevorthis, Skenidioides and the plectambonitoid Leptestiina. Very rare forms include Idiospira? and Palaeostrophomena together with possibly Biscuspina and Sowerbyella. The brachiopod revision supports the late Caradoc (early Katian) age indicated by the trilobite fauna. The trilobite fauna generally indicates a probable deeperwater environment and the brachiopod assemblage confirms an outer shelf environment. Although elements of the assemblage indicate affinity with the well-defined Late Ordovician Foliomena fauna, it probably occupied a more shoreward position.