We conduct phylogenomic analyses on the Opiliones superfamily Triaenonychoidea, a lineage with ~500 described species largely distributed throughout the temperate Gondwanan terranes. A stable classification of Triaenonychoidea has been hindered by the historical reliance on morphological characters now known to be unsuitable for classification. Based on genetic and morphological analyses we describe new families, genera, and species, reassess systematics, and provide a species-level checklist. Our study provides phylogenomic context for future evolutionary and systematic research across this diverse lineage.

Our understanding of evolutionary history of various organisms, including taxonomic changes based on them, does not always benefit from both molecular and morphological data. Here, we investigate the evolutionary history of a morphological character using the most comprehensive molecular phylogeny of the ‘Taygetis clade’, which is a diverse lineage of Nymphalidae found in the Neotropics. Two new closely related species from this group are described, and our molecular dating analysis suggests that these two species likely diverged 0.3 million years ago, representing a recent speciation event.

Distribution patterns of deep-sea benthic gastropods remain poorly known, yet such knowledge is crucial to approaching their systematics and understanding their diversity. With a focus on the raphitomid genera Gladiobela and Pagodibela, we combine genetic, shell, anatomy and distribution data to identify seven new species from Australia and beyond, which we here describe. Our findings suggest patterns of significant rarity in some species, with others exhibiting wide Indo-Pacific distributions. We argue that wide geographic ranges in deep-sea conoidean gastropods may be more common than previously assumed, which has implications for future systematics efforts on this hyperdiverse group.

Analysis of DNA reveals that a recently discovered form of Rhagada land snails in the Pilbara region of Western Australia is actually four species, with indistinguishable shells. This small, banded shell type has evolved multiple times, indicating that common shell form need not mean close relationship, and can thus mislead taxonomists. The uniformity of shell form over large areas of similar habitat is thus not due simply to common ancestry, but instead suggests adaptation to the local environment.

The epigean spider genus Cybaeus contains ~160 species in the Holarctic region. Although Cybaeus spiders are highly diverse in Japan, they have never been recorded from the Ryukyu Islands, which harbour various endemics. We present eight new Cybaeus species from the Ryukyu Islands with their molecular phylogeny. Our results provide further insights into their genital characters, retreats, and biogeographical pattern.