Mid-Dinantian brachiopod biofacies from western Ireland

Abstract

New silicified brachiopod faunas from lower and middle Vis~an horizons have been retrieved from the vicinity of Loughs Carra, Corrib and Mask in west Connaught. In addition, carbonate shell beds dominated by Linoprotonia are recorded from mid County Galway. At present over 40 species of brachiopod are known, from current sampling programmes and the literature, variably associated with bryozoan, coral, echinoderm, mollusc and trilobite faunas; microvertebrates such as sharks teeth are locally common. Four main assemblages are recognized; in ascending order, Arundian strata at Ardnasillagh, Lough Carra, Kilbeg Wood and Ballintober in a northern belt are variably dominated by Rhipidomelta, Schizophoria, Leptagonia, Rugosochonetes, Krotovia, Echinoconchus, Tylothyris, Punctospirifer and Spiriferellina. In addition to genera recorded from Arundian strata elsewhere, Streptorhynchus, Plicochonetes, Dictyoclostus, Pleuropugnoides and 'Spirifer' also occur in the diverse Kiltiernan fauna assembled last century. In a southern belt, possible Holkerian horizons at Dunsandle are less diverse, with faunas dominated by Composita, whereas limestones of Holkerian-early Asbian age at Kiltullagh Bridge have quite different faunas with Schizophoria, Brochocarina, Minythyra and Cleiothyridina; these faunas are more similar to the diverse Asbian assemblages described from County Fermanagh in the north of Ireland. In a central belt, in the Bunoghanaun area, Holkerian to early Asbian horizons are dominated by relatively thick shell beds in pure limestones with mainly opportunist large linoproductids; this fauna is not silicified.

Sedimentary context and palaeoecology of Gigantoproductus shell beds in the Mississippian Eyam Limestone Formation, Derbyshire carbonate platform, central England

“…Gigantoproductids were suited for living in high-energy environments (Ferguson 1978;Harper & Jeffrey 1996) where currents ensured a constant supply of sufficient oxygen and food passing over them. The consistent brachiopod orientation in the Gigantoproductus shell bed analysed at Ricklow Quarry, with umbos oriented pointing north, suggests currents were constant.…”

The Role of Spain in the Development of the Reef Brachiopod Faunas During the Carboniferous

“…Data from Ireland (Brunton, 1966(Brunton, , 1968(Brunton, , 1984(Brunton, , 1987Harper and Jeffrey, 1996) only marginally modify the picture. They have many genera and species in common with the Valdeteja Formation, which at first glance make the impression of Viséan faunas.…”

Revisiting the upper Visean mud mounds from Derbyshire (UK): the role of brachiopods in their growth

“…Brachiopod diversity and distribution are sensitive to environmental parameters such as substrate and food resources (e.g. Harper and Jeffrey 1996;Pérez-Huerta and Sheldon 2006;Angiolini 2007); hence, in brachiopod-rich mud mounds the combined study of lithofacies types and brachiopod communities provides fundamental information for the understanding of mud mound growth, depositional environment, water depth, and nutrient levels.…”