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Limestone outcrops that form a north-south belt approximately 1.4 km long, 15 km east of Manilla and previously referred to as the Uralba Beds, and associated rocks, are shown to be an olistostromal component of the Wisemans Arm Formation. Elongate olistoliths up to 100 m in length are flanked by limestone conglomerate with clasts set in a volcaniclastic matrix derived from a range of volcanic rock types. Volcanic olistoliths, including a mass of ankaramitic basalt, are also present. Conodont faunas of differing ages were obtained from various outcrops. A Late Ordovician (Eastonian, Ea3) fauna of over 400 elements from some outcrops is identical to one recently documented from elsewhere in the Wisemans Arm Formation. A small Early Silurian (late Llandovery-early Wenlock) fauna from four outcrops (including two formerly thought to be Ordovician) comprises the first documented conodont fauna of this age from the New England Fold Belt.

The new conodont Webbygnathus munusculum gen. et sp. nov. is described from Eastonian (early Late Ordovician) strata from the central part of the Parkes Zone of the Lachlan Fold Belt and the New England Fold Belt in New South Wales. In the type area south of Gunningbland, central New South Wales, the genus occurs associated with macrofossils of the coral/stromatoporoid assemblage Fauna II (early Eastonian or Ea2); in the New England region it has been obtained from strata on both sides of a major structural feature, the Peel Fault, the associated conodont assemblages indicating an age equivalent to that of coral/stromatoporoid assemblage Fauna III or late Eastonian (Ea3). The apparatus of this species, as presently known, comprises two pectiniform elements, one stellate with a four-rayed basal cavity, the other fundamentally pastinate, with a three-rayed basal cavity.