Idiosoma cupulifex is a trapdoor spider in the Arbanitinae subfamily of the Idiopidae family.[1] It was first described as Aganippe cupulifex by Barbara York Main in 1957.[1] [2] In 2017 Michael Rix and others transferred it to the genus, Idiosoma, to give the name Idiosoma cupulifex,[3] (the name accepted by the Australian Faunal Directory, and the World Spider Catalog,[4] and GBIF[5]).
It is found only in the south-west of Western Australia, in open forest and woodland.[1]