The aim of this report is to provide a framework within which future earth science researchers of the Sydney Basin in the Triassic Period can work to rapidly access information relevant to their particular field of study. Information on the geology, flora and fauna and ecosystems has been extracted and summarized from an extensive range of papers published from the late 1800s to present day. In many cases the taxonomic classification of specimens has changed over the years as more data has come to light. The history of these changes has been noted. This information is backed by specimen lists and illustrated by images of selected specimens sourced from the extensive palaeontological collection of the Australian Museum, augmented by additional images from the collection of the Geological Survey of New South Wales. The major Triassic geological structures of the Sydney Basin are the Narrabeen Group, the Hawkesbury Sandstone and the Wianamatta Group. This report provides a consolidated review of data presently available for the Narrabeen Group. Future reports will cover the Hawkesbury Sandstone and the Wianamatta Group in a similar manner.