Synsphyronus attiguus is a species of pseudoscorpion in the Garypidae family. It is endemic to Australia. It was described in 1987 by Australian arachnologist Mark Harvey. The specific epithet attiguus (Latin: 'touching' or bordering') refers to its close geographical and morphological relationship with Synsphyronus absitus.
The body length of the females is 3.7âÂÂ4.2 mm; that of males 2.9âÂÂ3.5 mm. Colouration is dark yellowish-brown.
The species occurs in the Flinders Ranges of South Australia. The type locality is Mernmerna, 33 km north of Hawker, where the holotype was found under a rock.
The pseudoscorpions are terrestrial predators.