Inarticulate brachiopods from the Late Ordovician of New South Wales, and their palaeoecological significance

Abstract

Late Ordovician formations in central-western New South Wales yield lingulide and acrotretide inarticulate brachiopods occurring in lithologies and faunal assemblages indicative of deeper-water (outer shelf-slope) environments of deposition, associated with volcanic island chains in the Tasman Geosyncline. Two new, monotypic, genera, Anomaloglossa and Casquella of subfamily Glossellinae, and six new species (Anomaloglossa porca, Casquella bifida, Conotreta? hetera, Elliptoglossa adela, Paterula giganta and P. malongulliensis) are described and illustrated; two additional forms — Elliptoglossa sp., Paterula sp. — are recognised. Palaeoecology of these Late Ordovician species, with particular emphasis on life orientation and mode of attachment, is deduced from functional morphology and faunal associations. Casquella is a minor component of a high diversity trilobite-strophomenid assemblage occupying an outer shelf habitat. The gigantic Anomaloglossa forms part of a graptolite-sponge-trilobite-brachiopod ass...