The trapdoor spider family Migidae has a classical Gondwanan distribution and is found on all southern continents except the Indian region. The Australian fauna consists of three genera including Moggridgea O. P. Cambridge from south-western Australia and Kangaroo Island, South Australia; Moggridgea is otherwise widespread throughout Africa. The sole named species of Moggridgea from Western Australia, M. tingle Main, and its unnamed relatives are the subject of the present paper, which was stimulated by concern for the long-term persistence of populations, and the discovery of deep genetic divergences between populations. A phylogeny of the Western Australian species relative to African and South Australian Moggridgea was generated using molecular COI and ITS rDNA data, and based on both molecular and morphological criteria we conclude that the Western Australian taxa should be removed from Moggridgea and transferred to a new genus, Bertmainius. The seven species are delimited using both morphological and molecular criteria: B. tingle (Main) (the type species), and six new species, B. colonus, B. monachus, B. mysticus, B. opimus, B. pandus and B. tumidus. All seven species are considered to be threatened using IUCN criteria, with the major threatening processes being inappropriate fire regimes and climate change.