New antiarchs (Placodermi) from the Hunter Siltstone (Famennian) near Grenfell, N.S.W.

Abstract

The Hunter Siltstone near Grenfell, New South Wales, contains a rich Upper Devonian fish fauna including the sinolepid Grenfellaspis and the new antiarchs Bothriolepis grenfellensis sp. nov. and Remigolepis redcliffensis sp. nov. Bothriolepis grenfellensis sp. nov. is the first bothriolepid species described from N.S.W., and R. redcliffensis sp. nov. is the first species of Remigolepis described from Australia. Traditionally, the Hunter Siltstone was considered to be uppermost Famennian or earliest Carboniferous in age based on the presence of Grenfellaspis, and the related taxon Sinolepis, which is known from the Wutung and Sanmentan formations of southeastern China. However, available data indicates the Hunter Siltstone may be early Famennian in age. Ongoing work suggests that all Famennian Bothriolepis from N.S.W., including B. grenfellensis, possess a trifid preorbital recess, but differ in other aspects of headshield morphology. In North China, the Famennian Zhongning Formation contains six species o...