New species of Aphelognathus, Belodina, Taoqupognathus, and Yaoxianognathus have been identified in the Late Ordovician Cliefden Caves Limestone Group in central-western New South Wales, Australia. Of the Aphelognathus species, Aphelognathus percivali n. sp. and A. webbyi n. sp. occur in the basal Gleesons Limestone Member and A. packhami n. sp. and A. stevensi n. sp. occur 30 m higher in the Wyoming Limestone Member. It seems likely from the similarity of several of the elements that A. packhami is closely related to A. percivali, and A. stevensi to A. webbyi. Yaoxianognathus wrighti n. sp. occurs in the Gleesons Limestone Member but not in the Wyoming Limestone Member. Belodina confluens, Belodina hillae n. sp., Belodina n. sp., Panderodus gracilis, Taoqupognathus philipi n. sp., and Phragmodus? tunguskaensis occur at both horizons. The conodonts suggest a middle to late Caradocian (mid-Shermanian to mid-Edenian) age for the lowest part of the Cliefden Caves Limestone. The occurrence in southeastern Australia of the forms Taoqupognathus, Yaoxianognathus, and Phragmodus? tunguskaensis suggest affinities to coeval faunas in China and eastern Siberia. The four new species of Aphelognathus are distinct from known species in the Late Ordovician of North America and Europe but they may help characterize a paleobiogeographic region that includes eastern Australia and southeast Asia.
Countermapping: New South Wales and Southeast Asia
