For the first time, paederine rove beetle fossils from Baltic amber are included in a statistical phylogenetic analysis, resulting in the description of two new species (Micrillus electrus, sp. nov.; Scymbalium phaethoni, sp. nov.). The analysis showed that the extant genera Micrillus and Scymbalium are not monophyletic and confirmed that they form a lineage outside the subtribe Lathrobiina, wherein they were classified. The disjunct distribution and ecological preferences of the lineage indicate the diverse palaeoenvironment of the Eocene amberiferous forest.

The Edwards–Trinity aquifer system in Texas is known to possess a rich diversity of stygobitic invertebrates. Collection efforts in Terrell County reveal an enigmatic new genus and species of bogidielloid amphipod. This species is easily distinguished from all other members of the Bogidielloidea and morphologically appears most similar to the sympatric Parabogidiella americana. Both species form a phylogenetic clade outside Bogidiellidae sensu stricto. A new family is raised to accommodate these species and further molecular work with this poorly understood group is encouraged.

Aenigmetopia is the only Australian endemic genus of the flesh fly subfamily Miltogramminae. This genus was previously known from a single species and specimens had been neither collected nor studied since the early 1900s. This study utilises integrative systematics to describe four new species of genus Aenigmetopia and explores its phylogenetic placement among the miltogrammines for the first time, resolving a novel sister-group relationship between this genus and Metopia.

In this study, we analysed specimens of two species of pantropical sea slugs, Bursatella leachii and Stylocheilus striatus, comparing morphology and DNA sequences of individuals across all the distributional range. Our results reveal that there are two distinct Bursatella species and three distinct species of Stylocheilus, which we formally redescribed in this paper. An additional genus, Phycophilla, discovered from a previously misidentified specimen, was resurrected from synonymy in this study.