Reappraisal of Mesozoic fishes and associated invertebrates and flora from Talbragar and Koonwarra, eastern Australia

Abstract

Eastern Australia has two major Mesozoic fossil localities. The Talbragar Fish Bed in central west New South Wales contains an assemblage of Upper Jurassic fishes, plants and insects. The Koonwarra Fossil Bed, in South Gippsland, Victoria, has an assemblage of Lower Cretaceous fishes, plants and insects. The geological settings of these localities are described. Each locality has a common genus of fish that was originally described as Leptolepis. The names of both these fish have been changed, the Talbragar one to Cavenderichthys talbragarensis and the Koonwarra one to Waldmanichthys koonwarri. Both of these fish have been placed into the Family Luisiellidae, together with a Patagonian fish, Luisiella feruglioi. Each locality also has a member of the family Archaeomenidae: Archaeomene tenuis from Talbragar and Wadeichthys oxyops from Koonwarra. The relationships of these and other fish have been discussed by various authors over the last 20 years and a summary of these comments is presented, as well as a brief comparison between the plants of both localities. The localities of Talbragar, Koonwarra and the Argentinian fishes during the Mesozoic appear to have similar palaeo-environmental settings, which may explain the similarities in the assemblages. The Australian localities contain well-preserved specimens which shed light on the diversity and extent of fishes in southern Gondwana, a region otherwise poorly represented in the fossil record.