Post-Eocene climate change across continental Australia and the diversification of Australasian spiny trapdoor spiders (Idiopidae: Arbanitinae)

•We investigated the phylogeny of Australasian Idiopidae, using new markers and a TAS approach.•We tested the origins of arid-adapted lineages in both space and time.•We show that t hree lineages of Idiopidae diversified in the arid zone during the Miocene.•We show that phragmosis and the loss of burrow doors evolved multiple times.•Idiopids in New Zealand are the result of dispersal from Australia rather than ancient vicariance.