Biostratigraphic review of the Silurian tabulate corals and chaetetids of Australia

Abstract

The biostratigraphic distribution of the Silurian Tabulata and Chaetetida of Australia can informally be described in terms of four successive coral assemblages. The earliest Bridge Creek Assemblage (Rhuddanian‐Aeronian) contains abundant halysitids and is not geographically widespread. Species of this assemblage tend to be holdovers from Late Ordovician faunas. A major radiation event occurred at the time of the Quarry Creek Assemblage (Telychian‐early Sheinwoodian), involving favositids, heliolitids, halysitids, and other groups. This may indicate the onset of conditions favourable to corals over widespread areas of eastern Australia. The late Sheinwoodian‐earliest Gorstian Dripstone Assemblage is characterised by a continued expansion in the number of species of favositids, the appearance of auloporids, and a contraction in the number of species of sarcinulids, multi‐soleniids, and halysitids. Favositids continued to dominate the youngest Hatton's Corner Assemblage (Gorstian‐Pridoli), but halysitids almost became extinct by the end of the Ludlow. Faunas of Pridoli age are neither abundant nor well studied, but appear to be reduced continuations of earlier faunas. A number of tabulate taxa are identified as possibly useful biostratigraphic indicators in Silurian sequences.

Keywords:

• Silurian
• Tabulata
• Chaetetida
• Biostratigraphy
• Bridge Creek Assemblage
• Quarry Creek Assemblage
• Dripstone Assemblage
• Hatton's Corner Assemblage
• Australia

Notes

Corresponding author.