Idiosoma sigillatum is a species of mygalomorph spider in the Idiopidae family. It is endemic to Australia. It was described in 1870 by British arachnologist Octavius Pickard-Cambridge.[1]
The species occurs in south-west Western Australia, in the Swan Coastal Plain and Jarrah Forest bioregions, including the Darling Scarp and Rottnest Island, in open forest habitats. The type locality is Swan River (Perth).[1]
The spiders are fossorial, terrestrial predators. They construct burrows with trapdoors in plant litter on sandy-gravel soils, with a fan of twig-lines around the entrance.[1]