a Aerial map of main South Walker Creek fossil sites SW9, SWJ and SW3 with downstream site SWCC indicated by arrow. Megafauna taxa recovered from each site indicated by numbered silhouette: 1. Pallimnarchus sp. 2. ‘Quinkana’ sp., 3. Crocodylus sp. cf. C. porosus, 4. Varanus priscus, 5. Varanus sp. (large), 6. Dromaius sp., 7. Diprotodon optatum, 8. Phascolonus gigas, 9. Sedophascolomys sp. cf. S. medius, 10. Thylacoleo sp., 11. Palorchestes sp., 12. Macropus sp. (giant), 13. Protemnodon sp., 14. Notamacropus sp. (giant), 15. Osphranter sp. cf. O. rufus, 16. sthenurine. b Stratigraphic section A–Aʹ crossing through SW9, SWJ and SW3 (indicated by dashed line in (a)). Quaternary (Qa) alluvial sediment overlies dipping basement Permo-Triassic Rewan Group (Rw) bedrock (vertical exaggeration 5×). Fossil deposit surface expression at SW9 (c), SW3 (d) and SWCC (e). Summary of the diverse fossil remains recovered from SWC sites (see Supplementary Note 1 for detailed descriptions): f leaves and bivalves in situ at SW9; g Goodeniaceae seed; h Velesunio wilsoni bivalve; i insect elytron (?Curculionidae); j Pallimnarchus sp. osteoderm; k Crocodylus sp. cf. C. porosus osteoderm; isolated crocodile teeth from l Pallimnarchus, m Crocodylus sp. and n ‘Quinkana’; o Varanus priscus tooth; p Macropus sp. (giant) tibia in situ at SW9; q Varanus priscus dorsal vertebra; associated appendicular elements from Thylacoleo sp., r metacarpal, s phalange and t fibula; u Diprotodon optatum right dentary; v Macropus sp. (giant) humerus with crocodile puncture marks (indicated by arrows); w Articulated pelvis and caudal vertebrae of Phascolonus gigas from SW9; x associated hind limb of juvenile Protemnodon sp. from SW9. Scale bars equal 1 mm in (g, i); 5 mm in (h, j–t, v, x); 10 mm in (u); and 50 mm in (w).