Triaenomeros versus Neopachyloides: major males of misplaced Ecuadorian Ampycidae exhibit unexpected strong armature (Opiliones, Grassatores, Gonyleptoidea)

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  Triaenomeros versus Neopachyloides: major males of misplaced Ecuadorian Ampycidae exhibit unexpected strong armature (Opiliones, Grassatores, Gonyleptoidea) Abstract Ampycidae is a small Neotropical family of Gonyleptoidea (currently comprising a few dozen species) whose members have historically been scattered among unrelated harvestman taxa, so that its true composition is still being uncovered. Neopachyloides Roewer, 1913 (originally classified in Gonyleptidae, Pachylinae, but currently placed in Ampycidae) is newly considered a junior subjective synonym of Triaenomeros Roewer 1913 (currently in Gonyleptidae Gonyleptinae). Their respective type-species—Neopachyloides spinipes Roewer 1913 and Triaenomeros olivaceum (currently incorrectly inflected as olivaceus) Roewer 1913—are also synonymized with each other. Triaenomeros olivaceum occurs in the western Andean slope, with some conflicting original records from Chile. The genus in this work is firmly established in Ampycidae. T...

Gondwanan Relic or Recent Arrival? The Biogeographic Origins and Systematics of Australian Tarantulas

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Gondwanan Relic or Recent Arrival? The Biogeographic Origins and Systematics of Australian Tarantulas

Abstract

The composition of Australia’s fauna and flora has been largely assembled by two biogeographic processes, vicariance and long-distance dispersal and establishment. These patterns can be observed today through the survival of Gondwanan lineages contrasted with relatively recent colonization from south-east Asia, respectively. In general, the post-Gondwanan immigrant lineages from south-east Asia are taxa with traits that facilitate dispersal. Consequently, taxa like tarantulas (Araneae, Theraphosidae) that are largely pan-tropical but also have a low propensity for dispersal, are thought to be Gondwanan in origin. However, the Australian tarantulas are unsampled for phylogenomic studies and, as such, their classification and biogeographic origins have been long debated and are unresolved. Here we test if their current, morphology-based classification in Selenocosmiinae is accurate and assess whether the Australian tarantulas were present in Australia while it was part of Gondwana. We sample 369 tarantula specimens from across Australia, greatly expanding the geographic sampling of previous studies, to develop the first continent-wide phylogeny of the Australian tarantulas. To resolve the ‘back bone’ of the Australian tarantula phylogeny we generate 20 new transcriptomes for species of Australian tarantulas representing distinct lineages uncovered using mitochondrial sequence data and combine these new transcriptomes with published transcriptomic data. Through the recovery of ultra-conserved element (UCE) loci from transcriptomes and testing multiple data occupancy matrices, we find that the Australian clade is monophyletic and nested inside the largely Asian Selenocosmiinae. We find the Australian fauna are a relatively young radiation with a crown age of 8.3–18.8 Ma and we therefore reject the hypothesis of a Gondwanan origin for these animals and, instead, infer a recent dispersal from south-east Asia. Our findings indicate that they underwent a rapid radiation, possibly coinciding with their arrival into Australia. Our findings refute the monophyly of Selenocosmia and Coremiocnemis as currently recognised, and we remove Selenocosmia stalkeri from synonymy with Selenocosmia stirlingi.

Briggs, E. J., Foley, S., & Cook, L. G. (2025). Gondwanan relic or recent arrival? The biogeographic origins and systematics of Australian tarantulas. Molecular Phylogenetics and Evolution, 204, 108246. https://doi.org/10.1016/j.ympev.2024.108246