The Opiliones family Neopilionidae is restricted to South America, Africa, Australia, New Caledonia and New Zealand. Here we investigated the pattern and timing of diversification of Neopilionidae across Gondwana by sequencing three markers commonly used in Sanger-based molecular approaches. We recovered a well supported and stable clade including Ballarra and the Enantiobuninae from South America, Australia, New Caledonia and New Zealand, but excluding Vibone from South Africa. We further found a division between West and East Gondwana, with the South American Thrasychirus/Thrasychiroides always being sister group to an Australian–Zealandian (i.e. New Zealand + New Caledonia) clade. Our results identify several genus-level inconsistencies in Neopilionidae and several new lineages requiring formal description.

The Tasmanian Cave Spider (Hickmania troglodytes) is the only Australian lineage of Austrochilidae with all other members of the family in southern South America. Hickmania is an oddity in Austrochilidae because this is the only spider bearing posterior book lungs, tarsal spines and a process on male pedipalps. We assessed the family placement of this spider using genomic scale data and a variety of phylogenetic treatments. Based on our results, we formally transfer Hickmania to Gradungulidae, an assignment that conforms to the morphology, distribution and phylogenetic placement.

Only seven frenulate species are currently known along the Eurasian coast of the Arctic Ocean. In this paper, we describe a new genus and a new species of frenulates – Crispabrachia yenisey, gen. nov. et sp. nov. Here we present the morphological analysis of new genus. The molecular study included four markers (partial COI, 16S, 18S and 28S) and implemented Bayesian and Maximum likelihood phylogenetic approaches. The description of Crispabrachia gen. nov. is the first documented finding of frenulates in the Kara Sea at the estuary of the Yenisey River in rather shallow water (28 m).

Coelastrea aspera is a zooxanthellate scleractinian coral, widely distributed in the Indo-Pacific. Our analyses of reproduction, morphology and molecular phylogeny reveal that C. aspera is clearly separated into two main groups. Examination of the type materials leads us to conclude that one group represents the true C. aspera, whereas the second is C. incrustans comb. nov., herein re-established.

Corals of the genus Plexaurella are conspicuous sea fans from Caribbean and Brazilian reefs. Although known for more than a century, there was an uncertainty regarding on how many species comprised the group or in which family they should be placed. Herein, based on morphological and molecular evidence, we review the species of the genus and reconstruct the recent evolutionary history, concluding that eight species are valid, one of which is new. Our analyses also illustrate the need to establish a family for these corals, called Plexaurellidae.

Orb-weaving spiders of the genus Leucauge commonly occur in tropical regions worldwide. The systematics of these arachnids have been neglected because of the large number of species that occur and the difficulty in identifying species. We present the first comprehensive molecular phylogeny of the genus Leucauge and closely related genera. Our results indicate that the genera Opas, Opadometa, Mecynometa and Alcimosphenus are nested among species of Leucauge and we formalise the synonymy with Leucauge.

Despite the importance of geographical distribution for understanding the evolution and diversity of deep-sea snails, this remains poorly known. We combine genetic, shell, anatomical and distribution data from three genera to identify four new species from Australia and beyond that we describe here, with an emphasis on rare or endemic species. Our findings suggest that radula and protoconch features can help interpret genus-level relationships. We discuss the role of the environment in shaping the snails’ evolution.