Linguliformean brachiopod faunal turnover across the Ireviken Event (Silurian) at Boree Creek, central-western New South Wales, Australia

Late Llandovery (celloni? Zone) to early Wenlock (amsdeni Zone) linguliformean brachiopods (sensu WILLIAMS et al. 1996) from the Boree Creek Formation of central-western New South Wales are documented. Nine new taxa consist of: Lingulops austrinus sp. nov., Rowellella? parvicapera sp. nov., Schizotreta corrugaticis sp. nov., S. cristatus sp. nov., Acrosaccus cuniculum sp. nov., Artiotreta longispeta sp. nov., Acrotretella goodridgei sp. nov. and Opsiconidion angustus sp. nov. A further two species, one Acrotretella and one Opsiconidion are left in open nomenclature, because a lack of material precludes meaningful assessment. A new genus of Siphonotretida (new genus A) also occurs in the section. Faunal turnover across the Ireviken Event at Boree Creek is defined using the Datum Points identified by JEPPSSON (1997, 1998). Datum Points 1?, 2, 3, 4? and 6? can be identified at Boree Creek, based on lithological and faunal changes in conodont assemblages. The pre-event fauna commonly consists of 9 taxa, with R.? parvicapera sp. nov., S. cristatus sp. nov. and Art. longispeta sp. nov. the most common species. A small decline in abundance is recorded across Datum Point 1?, after which S. cristatus sp. nov. and Art. longispeta dominate the fauna. Severe reduction in diversity and abundance is recorded across Datum Points 2 and 3; this level corresponds also to the Llandovery-Wenlock boundary. Abundance and diversity remains low until Datum Point 4, where an increase occurs and the fauna becomes dominated by S. corrugaticis sp. nov. Other taxa, such as new genus A, Art. longispeta and A. cuniculum sp. nov. are also common after Datum Point 4. A second drastic reduction in abundance and diversity coincides with Datum Point 6, but may be related to a local shallowing event.27 page(s