Tardigrades are one of the main component of Antarctic fauna in terms of abundance, distribution and diversity. Antarctic tardigrades from Dronning Maud Land and Victoria Land, together with specimens from Italy and Greenland, were analyzed from morphological and molecular points of view. These analyses led to the erection of two new genera and the description of two new species.

The Burrup Peninsula, Western Australia, has the greatest diversity of Rhagada land snails of any comparable area. DNA sequencing demonstrates the presence of four species, including the morphologically variable endemic Rhagada ngurrana, sp. nov. With a distribution spanning only 9 km, this unique species poses challenges for conservation in an area of substantial resource development and invasive buffel grass.

Many katydids have wings that closely resemble leaves; however, it is unclear how often the leaf-like wings have been derived in this group. We show at least 15 independent derivations of the leaf-like wing in katydids. The leaf-like wings are not associated with higher rates of speciation indicating the wings are not an overall driver of speciation in this family.

The little known tropical Asian crab spider genus Pagida has remained taxonomically unrevised and has never been subjected to phylogenetic evaluation. Pagida is revised, a new species described and the single origin of the genus is demonstrated. This study further enhances our understanding of the relationships within the family of crab spiders.

A mitochondrial phylogeny has revealed shell shape not to be a reliable estimator for systematic relationships in the Australian arid zone camaenid Basedowena. We demonstrate that species previously placed in different genera for exhibiting divergent shell shapes are in fact closely related sharing the same general genital anatomy. Thus, in order to retain monophyletic genera, several species are being transferred to Basedowena, which emerges as the most speciose and widespread camaenid genus in arid Australia. In addition, four new species and one new genus are described.

Free-living sister taxa may act as good models for parasitic groups, since most parasites are difficult to be cultured and analysed independently of their hosts. We describe and illustrate a free-living nematode which may represent a reversion from parasitism, based on its unusual genetic characteristics. Future studies on the genetics of this ‘model’ nematode will provide insights into the control of vertebrate parasites.

The knowledge about Gastrotricha in Arctic region are virtually unknown. In our work for the first time we describe a new species and new genus from the Spitsbergen and include to the new established genus also Chaetonotus (Primochaetus) veronicae Kånneby, 2013 because of many morphological similarities. In our work we show how important is using methods of integrative taxonomy during gastrotrichs description.