The identity of a morphologically bizarre tapeworm discovered parasitising thresher sharks as part of a global survey has puzzled biologists for decades. In concert, molecular, developmental, histological and scanning electron microscopical data provide evidence for its membership in an otherwise morphologically homogeneous genus. The new species is described and the genus is heretically emended to accommodate the novel form.

Resource developments increase the need and opportunity to clarify taxonomy of local endemics. We used morphology and DNA to confirm relationships of Quistrachia snails in Western Australia’s Pilbara region, identify a new species, extend known distributions, and reveal forms that belong to new genera. Shells alone are taxonomically unreliable for these snails, highlighting the need for including DNA sequences.

Despite being the largest marine larvae known to date, the real identity of the ‘giant phyllosoma’ was a mystery for the last 200 years. The present study confirmed the identity of specimens collected from Coral Sea waters by using DNA barcoding methods. Our molecular and morphological analyses of these larvae provide new light on the evolution of marine lobsters.

Pontomyia is an exclusively marine and flightless insect that is poorly known due to its small size (about 1 mm), short adult life (maximum three hours), and peculiar habitat for an insect (coastal lagoons, bays or rock pools). This study reconstructs the evolutionary history of all four described species from the Indo-Pacific and an unnamed taxon from the western Atlantic, based on molecular and morphological evidence. Our results show that Pontomyia cottoni and a Caribbean larval population are the same species as P. natans, whose known range now encompasses all three ocean basins.

Although members of the phylum Nemertea are distributed globally (in freshwater, marine and terrestrial ecosystems), evolutionary relationships and species delimitations within certain groups have been the subject of much debate. Using molecular data from six loci for 133 terminals, we recover most of the major lineages as monophyletic, with the exception of Palaeonemertea. These results agree well with previous findings but advance our understanding of the evolutionary relationships regarding e.g. Hubrechtidae and Plectonemertidae.

We present a new species of marine flatworm that displays an unusual 'inverted' reproductive system configuration. Attempts to place the species phylogenetically using DNA yielded conflicting results depending on mode of analysis, but suggest affinity with two other families with which the new species shares some traits. The morphological novelties and phylogenetic challenges that our analyses present may be seen as indicative of the many remaining discoveries that stand to be made in flatworm systematics.

The enigmatic flightless stag beetles, Colophon, are endemic to the high-mountain regions of the fynbos biome, South Africa, and protected by law, yet little is known of their evolutionary history. This study aimed to determine their specific and phylogenetic status and to determine the main factors driving their evolution. Findings benefit scientifically based decisions on individual species conservation.