Narrow-clawed crayfish (Astacus leptodactylus Eschscholtz, 1823 species complex) is a widely distributed species, rarely studied, whose taxonomy and systematic are unresolved. The aim of this research was to elucidate the phylogenetic relationship between European and Asian populations, using mitochondrial molecular markers. The results showed that two distinct evolutionary lineages exist. These results are a basis for further studies dealing with taxonomy and phylogeographical history of this native European crayfish.

The first Mesoamerican endemic genus of bess beetles is described after Passalus guatemalensis and four new species. The monophyly of Ameripassalus was tested with a phylogenetic analysis that retrieved the genus as monophyletic. Finally, keys to identify adults of the genera of Passalini and to the species of Ameripassalus are provided.

Spider crabs in the family Mithracidae are common on both coasts of the Americas, but little is known about their evolutionary relationships. We have used molecular phylogenetic analyses and morphological examinations to revise relationships within this family and diagnose new genera. This revision lays the groundwork for revisions of other families of spider crabs using similar methods.

Glaucus is an emblematic marine gastropod that lives floating upside-down at the surface of tropical and subtropical oceans. Analysis of DNA sequence data and morphological features of Glaucus collected worldwide revealed the existence of five distinct species, three of them new to science. Differences in the reproductive anatomy of some species suggest a role of sexual selection in Glaucus speciation.

Giant pill-millipedes (order Sphaerotheriida) belong to the iconic invertebrate taxa of Australia, despite the fact that their genus and even family assignment was still unclear. Based on an analysis of 100 morphological characters and studies of ancient type material it was discovered that the Australian Sphaerotheriida fauna is unique, with species of two different Sphaerotheriida families occurring in sympatry: the Procyliosomatidae, which also occur in New Zealand; and the endemic Cyliosomatidae.

Although corals are among the most important bio-building organisms in marine ecosystems, phylogenetic approaches based on morphological characters are still poorly reliable. This study tested the usefulness of cnidae as a phylogenetic source of information. Our observation and analyses based on a set dendrophylliid species indicate that cnidae are key and additional characters in order to clarify the phylogenetic relationships in scleractinian corals.