Preliminary report on the biostratigraphy of new placoderm discoveries in the Hervey Group (Upper Devonian) of central New South Wales

WA Museum Records and Supplements | Updated 10 years ago

Abstract - Re-mapping during 1994-96 of the Upper Devonian on the Parkes and Grenfell 1:100,000 map sheets was the first systematic field examination of this area by an experienced vertebrate palaeontologist. This resulted in the discovery of some 40 new fossil localities (mostly fish) at various horizons within the Hervey Group. Two new fish occurrences, in sediments associated with the underlying Dulladerry Volcanics, require an age revision from Early to late Middle Devonian for the termination of Devonian volcanism in central New South Wales. The age of the Canowindra fossil fish fauna is uncertain, but may be as old as late Frasnian, rather than Famennian as was previously assumed. Correlations across the Lachlan River are clarified, and a new locality for the sinolepid antiarch Grenfellaspis is reported from near the top of the Bumberry Formation. A fish fauna from higher in the sequence includes an antiarch with an armour 1-2 m long, of comparable size to similar material from South China, which supports a latest Devonian Asian connection with East Gondwana. Preliminary analysis of faunal content is used to propose a provisional succession of six faunal zones, to improve the resolution on the Late Devonian part of the macrovertebrate zonation for East Gondwana.