Palaeoecology and palaeoenvironment of the Jurassic Talbragar Fossil Fish Bed,Gulgong, New South Wales,Australia

BEATTIE, R.G. & AVERY, S., December 2012. Palaeoecology and palaeoenvironment of the Jurassic Talbragar Fossil Fish Bed, Gulgong, New South Wales, Australia. Alcheringa 36, 451–465. ISSN 0311-5518.

The Talbragar Fossil Fish Bed has produced a significant number and variety of insect fossils, including the orders Hemiptera, Coleoptera, Orthoptera, Plecoptera, Odonata, Neuroptera, Diptera, Hymenoptera and Mecoptera. Hemiptera are the most common insects. Coleoptera are both common and diverse. Both orders include terrestrial and aquatic species. The other insect orders represented are less common. Many of the insect fossils discovered were previously unknown in the Australian region during the Jurassic, and the new records extend their palaeogeographic range into southeastern Gondwana. A recent collection of insects, fish, coprolites, gastropods, bivalves, bark, leaves, fruiting bodies, burrows and other ichnofossils supports a model of a shallow-water-lake palaeoenvironment at the northern end of the deposit, grading to a shoreline palaeoenvironment towards the southern end of the deposit. The existence of a productive lake supporting a large population of fish and a diverse, aquatic/shoreline and terrestrial woodland fringe palaeoecosystem, dominated by insects and woody plants, is demonstrated. There is no evidence of tetrapods. The Talbragar Fossil Fish Bed has similarities to Type A and B Mesozoic lake deposits reported from Transbaikalia. Culicimorph pupae are numerous and may have filled a significant niche near the base of the aquatic palaeoecosystem. Other immature aquatic insects are rare. The generally articulated nature of the fossil insects is interpreted to have resulted from a sudden but low-energy burial event.