Idiosoma nigrum, also called black rugose trapdoor spider, occurs only in south-western Western Australia, in dry woodlands east of the Darling Scarp and north to Moore River.

Females can reach a length of about 30mm, males about 18mm.

[1] Idiosoma nigrum digs burrows up to 32 cm deep.

[2] The species name is derived from Latin Niger "black".

Data related to Idiosoma nigrum at Wikispecies