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

The formation and spread of the Australian arid zone during the Neogene was a profoundly transformative event in the biogeographic history of Australia, resulting in extinction or range contraction in lineages adapted to mesic habitats, as well as diversification and range expansion in arid-adapted taxa (most of which evolved from mesic ancestors). However, the geographic origins of the arid zone biota are still relatively poorly understood, especially among highly diverse invertebrate lineages, many of which are themselves poorly documented at the species level. Spiny trapdoor spiders (Idiopidae: Arbanitinae) are one such lineage, having mesic 'on-the-continent' Gondwanan origins, while also having experienced major arid zone radiations in select clades. In this study, we present new orthologous nuclear markers for the phylogenetic inference of mygalomorph spiders, and use them to infer the phylogeny of Australasian Idiopidae with a 12-gene parallel tagged amplicon next-generation sequencing approach. We use these data to test the mode and timing of diversification of arid-adapted idiopid lineages across mainland Australia, and employ a continent-wide sampling of the fauna's phylogenetic and geographic diversity to facilitate ancestral area inference. We further explore the evolution of phenotypic and behavioural characters associated with both arid and mesic environments, and test an 'out of south-western Australia' hypothesis for the origin of arid zone clades. Three lineages of Idiopidae are shown to have diversified in the arid zone during the Miocene, one (genus Euoplos) exclusively in Western Australia. Arid zone Blakistonia likely had their origins in South Australia, whereas in the most widespread genus Aganippe, a more complex scenario is evident, with likely range expansion from southern Western Australia to southern South Australia, from where the bulk of the arid zone fauna then originated. In Aganippe, remarkable adaptations to phragmotic burrow-plugging in transitional arid zone taxa have evolved twice independently in Western Australia, while in Misgolas and Cataxia, burrow door-building behaviours have likely been independently lost at least three times in the eastern Australian mesic zone. We also show that the presence of idiopids in New Zealand (Cantuaria) is likely to be the result of recent dispersal from Australia, rather than ancient continental vicariance. By providing the first comprehensive, continental synopsis of arid zone biogeography in an Australian arachnid lineage, we show that the diversification of arbanitine Idiopidae was intimately associated with climate shifts during the Neogene, resulting in multiple Mio-Pliocene radiations.

Taxonomic revision of the Neotropical spiders of the genus Idiops Perty, 1833 (Araneae, Idiopidae), with description of four new species

Neotropical species of the genus Idiops Perty, 1833 are reviewed, and four new species are described from Brazil: I. duocordibus Fonseca-Ferreira, Guadanucci & Brescovit sp. nov., I. guri Fonseca-Ferreira, Guadanucci & Brescovit sp. nov., I. mocambo Fonseca-Ferreira, Guadanucci & Brescovit sp. nov. and I. sertania Fonseca-Ferreira, Guadanucci & Brescovit sp. nov. The majority of species are redescribed based on the examination of the types and extensive material. Males of I. petiti (Guérin, 1838), I. rastratus (Pickard-Cambrige, 1889), I. rohdei Karsch, 1886 and I. nilopolensis Mello-Leitão, 1923, and females of I. fuscus Perty, 1833 and I. pirassununguensis Fukami & Lucas, 2005, hitherto unknown, are described for the first time. Idiops nilopolensis, considered a nomen dubium, is revalidated. Idiops fulvipes Simon, 1889 is synonymized with I. argus Simon, 1889, and I. santaremius (Pickard-Cambrige, 1896) is synonymized with I. petiti. Neotypes are designated for Idiops fuscus, I. nilopolensis and I. siolii (Bücherl, 1953). Idiops bonapartei Hasselt, 1888 is considered species inquirendae, since the type is an immature female. Finally, an updated distribution map of Neotropical species is included. The genus now has 24 species in the Neotropical region.