This report critically reassesses the biomarker geochemistry of the crude oil show encountered in the Wilkatana 1 well, using new analytical data, then compares its molecular composition with that of other Australian Cambrian oils, and discusses the implications of this historic oil discovery in the Arrowie Basin for the prospectivity of the Early Cambrian sedimentary rocks of the adjacent Stansbury Basin. Four important conclusions have been drawn from the current work: 1. Waxy, paraffinic-naphthenic reservoir bitumen from the Early Cambrian Wilkawillina Limestone in Wilkatana 1 contains a diverse assemblage of biomarker hydrocarbons, including acyclic isoprenoid alkanes, steranes, tricyclic and tetracyclic terpanes, and triterpanes. 2. These molecular fossils indicate that the Arrowie Basin's only oil show was derived from marine organic matter, comprising the remains of primitive eukaryotic algae and prokaryotic microorganisms (bacteria, cyanobacteria). This organic matter accumulated under suboxic conditions; and the resulting source rock lithofacies was a calcareous shale. 3. The residual, (?) water-washed Wilkatana 1 crude is relatively immature, having been expelled from its source rock (probably in the Oraparinna Shale or Mernmerna Formation) at an estimated vitrinite reflectance of ~0.6-0.7%. 4. Black shales within the stratigraphic equivalents of these formations in the Stansbury Basin (viz. Heatherdale Shale and Parara Limestone) are likely to have generated and expelled Wilkatana-type oil. The timing of this oil migration event is currently being investigated.