Early Devonian Ostracoda from the Norton Gully Sandstone, southeastern Australia

The Lower Devonian (Emsian) Norton Gully Sandstone contains rich invertebrate fossil faunas including ostracods. Seven ostracod taxa are recognized and illustrated herein: Bungonibeyrichia copelandi, Bungonibeyrichia wooriyallockensis, Bungonibeyrichia treslata sp. nov., Bungonibeyrichia australiae, Bairdiocypris sp., and two indeterminate genera. The ostracods are preserved in sandstone and mudstone as natural moulds. There are two distinct biofacies identified within the Norton Gully Sandstone: one dominated by ornate ostracods belonging to Bungonibeyrichia; and the other by smooth species of Bairdiocypris. We also conclude that most southeast Australian species previously placed in Velibeyrichia are more appropriately placed in Bungonibeyrichia on the basis of lobe morphology. Consequently, both these genera can be recognized as having discrete Silurian-Devonian palaeobiogeographical distributions, with Velibeyrichia spp. occurring in the shallow seas of Laurentia, while Bungonibeyrichia spp. was restricted to shallow seas around eastern Gondwana.