Synsphyronus callusSynsphyronus callus is a species of pseudoscorpion in the Garypidae family. It is endemic to Australia. It was described in 1947 by American arachnologist Clarence Clayton Hoff.DescriptionThe body length of the holotype female is 3.3 mm. The colour is brown.Distribution and habitatThe species occurs in south-west Western Australia in rocky coastal habitats. The type locality is Rottnest Island, with a paratype specimen obtained at Cottesloe Beach near Perth.BehaviourThe pseudoscorpions are terrestrial predators.