Total‐evidence analysis of an undescribed fauna: resolving the evolution and classification of Australia’s golden trapdoor spiders (Idiopidae: Arbanitinae: Euoplini)

Disconnecting trapdoors: Phylogenomic analyses reveal evolutionary contrasts in trapdoor spiders with intercontinental distribution (Idiopidae, Idiopinae)

Among Mygalomorphae spiders, the family Idiopidae is the second most diverse, consisting exclusively of trapdoor spiders and is divided into three subfamilies: Arbanitinae, Genysinae, and Idiopinae. The subfamily Idiopinae, distinguished mainly by anterior lateral eyes that project forward, includes 153 species across seven genera, distributed throughout South America, Africa, and parts of Asia. Within this subfamily, the genus Idiops includes the greatest diversity and is the only genus recorded in both the New and Old Worlds. Utilizing a taxon set from the Neotropical and Afrotropical regions, with specimens collected from 1947 to 2021, our study provides the first phylogenomic analysis of the family based on Ultraconserved Elements (UCEs). To assess the monophyly of Idiopinae and Idiops, as well as the relationships among genera within the subfamily, we conducted phylogenetic analyses employing maximum likelihood, Bayesian inference, and coalescent-based methods. The phylogenetic trees reveal that Idiopinae forms a monophyletic lineage, split into two geographically distinct groups: one with African species and the other with Neotropical species. We did not recover monophyly of the genus Idiops; Neotropical Idiops form a monophyletic lineage, while African Idiops species group with Titanidiops, forming a sister lineage to the remaining African Idiopinae. The relationship between the phylogenetic results obtained and the main morphological differences observed among the genera is discussed. Finally, our study challenges the monophyly of Idiopidae by including Neocteniza, which is found to be an independent lineage sister to Ctenizidae and the rest of Idiopidae.

Dated phylogeny and ancestral range estimation of sand scorpions (Buthidae: Buthacus) reveal Early Miocene divergence across land bridges connecting Africa and Asia

Sand scorpions of the genus Buthacus Birula, 1908 (Buthidae C.L. Koch, 1837) are widespread in the sandy deserts of the Palearctic region, occurring from the Atlantic coast of West Africa across the Sahara, and throughout the Middle East to Central Asia. The limits of Buthacus, its two species groups, and many of its species remain unclear, and in need of revision using modern systematic methods. The study presented here set out to investigate the phylogeny and biogeography of the Buthacus species occurring in the Levant, last studied in 1980. A phylogenetic analysis was performed on 104 terminals, including six species collected from more than thirty localities in Israel and other countries in the region. Three mitochondrial and two nuclear gene loci were sequenced for a total of 2,218 aligned base-pairs. Morphological datasets comprising 22 qualitative and 48 quantitative morphological characters were compiled. Molecular and morphological datasets were analyzed separately and simultaneously with Bayesian Inference, Maximum Likelihood, and parsimony. Divergence time and ancestral range estimation analyses were performed, to understand dispersal and diversification. The results support a revised classification of Levantine Buthacus, and invalidate the traditional species groups of Buthacus, instead recovering two geographically-delimited clades, an African clade and an Asian clade, approximately separated by the Jordan Valley (the Jordan Rift Valley or Syro-African Depression), the northernmost part of the Great Rift Valley. The divergence between these clades occurred in the Early Miocene (ca. 19 Ma) in the Levant, coinciding temporally with the existence of two land bridges, which allowed faunal exchange between Africa and Asia.

Diversification of the mygalomorph spider genus Aname (Araneae: Anamidae) across the Australian arid zone: Tracing the evolution and biogeography of a continent-wide radiation

The assembly of the Australian arid zone biota has long fascinated biogeographers. Covering over two-thirds of the continent, Australia's vast arid zone biome is home to a distinctive fauna and flora, including numerous lineages which have diversified since the Eocene. Tracing the origins and speciation history of these arid zone taxa has been an ongoing endeavour since the advent of molecular phylogenetics, and an increasing number of studies on invertebrate animals are beginning to complement a rich history of research on vertebrate and plant taxa. In this study, we apply continent-wide genetic sampling and one of the largest phylogenetic data matrices yet assembled for a genus of Australian spiders, to reconstruct the phylogeny and biogeographic history of the open-holed trapdoor spider genus Aname L. Koch, 1873. This highly diverse lineage of Australian mygalomorph spiders has a distribution covering the majority of Australia west of the Great Dividing Range, but apparently excluding the high rainfall zones of eastern Australia and Tasmania. Original and legacy sequences were obtained for three mtDNA and four nuDNA markers from 174 taxa in seven genera, including 150 Aname specimen terminals belonging to 102 species-level operational taxonomic units, sampled from 32 bioregions across Australia. Reconstruction of the phylogeny and biogeographic history of Aname revealed three radiations (Tropical, Temperate-Eastern and Continental), which could be further broken into eight major inclusive clades. Ancestral area reconstruction revealed the Pilbara, Monsoon Tropics and Mid-West to be important ancestral areas for the genus Aname and its closest relatives, with the origin of Aname itself inferred in the Pilbara bioregion. From these origins in the arid north-west of Australia, our study found evidence for a series of subsequent biome transitions in separate lineages, with at least eight tertiary incursions back into the arid zone from more mesic tropical, temperate or eastern biomes, and only two major clades which experienced widespread (primary) in situ diversification within the arid zone. Based on our phylogenetic results, and results from independent legacy divergence dating studies, we further reveal the importance of climate-driven biotic change in the Miocene and Pliocene in shaping the distribution and composition of the Australian arid zone biota, and the value of continent-wide studies in revealing potentially complex patterns of arid zone diversification in dispersal-limited invertebrate taxa.

Systematics of the Australian golden trapdoor spiders of the Euoplos variabilis-group (Mygalomorphae : Idiopidae : Euoplini): parapatry and sympatry between closely related species in subtropical Queensland

The Australian golden trapdoor spiders of the tribe Euoplini (family Idiopidae) are among the most abundant and diverse of mygalomorph lineages in subtropical eastern Australia. Throughout this highly populated area, species in the monophyletic Euoplos variabilis-group are largely ubiquitous; however, species delimitation has long proven difficult in the group because species are morphologically very similar and have parapatric or even sympatric distributions. We address these challenges in the variabilis-group, and explore the phylogeny and taxonomy of species using an integrative systematic approach. In doing so, we apply a conservative, pragmatic methodology, naming only species for which adequate data are available (namely sequence data and unequivocally linked male specimens), and explicitly stating and mapping material that could not be linked to a species, to aid future research on the group. We describe five new species from south-eastern Queensland –E. booloumba sp. nov., E. jayneae sp. nov., E. raveni sp. nov., E. regalis sp. nov. and E. schmidti sp. nov.; we redescribe two previously named species – E. similaris (Rainbow & Pulleine, 1918) and E. variabilis (Rainbow & Pulleine, 1918); and we reillustrate the recently described E. grandis Wilson & Rix, 2019. The nominate species, E. variabilis, is shown to have a far smaller distribution than previously thought, and E. similaris is given a modern taxonomic description for the first time. A key to adult male specimens is also provided. This study further reveals a case of sympatry between two species within the variabilis-group; both E. raveni sp. nov. and E. schmidti sp. nov. occur in the Brisbane Valley, south of the Brisbane River – a notable result given that closely related mygalomorph species usually occur allopatrically. This work updates what is currently known of the phylogeny and diversity of one of the dominant mygalomorph lineages of subtropical eastern Australia, resolving a complex and highly endemic fauna. http://zoobank.org/urn:lsid:zoobank.org:pub:A4FB92F6-EFFF-4468-B1D8-000D69923996