Ordovician sphinctozoan sponges from central New South Wales

Abstract

Sphinctozoan sponges are described and illustrated for the first time from Late Ordovician sequences, from the Belubula Limestone and the Angullong Tuff of the Cliefden Caves area, central New South Wales. The occurrences help to bridge the gap in the record between earliest known, Middle Cambrian, and later, Early Devonian, forms reported recently from other New South Wales localities. The sphinctozoans appear to have had a restricted distribution in their Early Palaeozoic history, mainly confined to island-arc shelf areas of eastern Australia and possibly similar settings of the Palaeo-Pacific rim in western North America. The new genus and species, Belubulaia packhami, is described from silicified material in the lower part of the Belubula Limestone near Little Boonderoo and Licking Hole Creek. A second new genus and species, Angullongia vesica, is much larger, calcareous and from an unnamed thin limestone unit of the Angullong Tuff on the property of Millamolong. Together these new genera constitute the new family Angullongiidae characterized by having large, spoutlike ostia as well as prosopores, and vesicular filling of porous chambers.