show Abstracthide AbstractPettalidae is a family of mite harvestmen that inhabits the former circum-Antarctic Gondwanan terranes, including southern South America, South Africa, Madagascar, Sri Lanka, Australia and New Zealand. Australia is home to two pettalid genera, Austropurcellia, in northern NSW and QLD and Karripurcellia, in WA, with a large distributional gap between these two parts of the Australian continent. Here we report specimens of a new pettalid from South Australia, Archaeopurcellia eureka, gen. et sp. nov., closing the large distributional gap of Australian pettalids. Phylogenetic analyses using traditional Sanger markers as well as ultra-conserved elements (UCEs) reveal that the new genus is related to the Chilean Chileogovea, instead of to any of the other East Gondwanan genera. This relationship of an Australian species to a South American clade can be explained by the Antarctic land bridge connecting these two terranes, a connection that was maintained with Australia until 45 mya. The UCE dataset also shows the promise of using museum specimens to resolve relationships within Pettalidae and Cyphophthalmi.