Fig. 1. Helical burrows in extant taxa. (A) Top-down view of aVaranus panoptes nesting burrow from Australia (J. S. Doody). (B) Side view of a Varanus gouldii nesting burrow from Australia (J. S. Doody). (C) Diagram depicting Varanus gouldii nesting burrows (Doody et al., 2018). (D) Casts of scorpion burrows (top panels) and entrances (bottom panels) from Australia (Hasiotis and Bourke, 2006).