Echiniscus siticulosus (Echiniscidae: spinulosus group), a new tardigrade from Western Australian scrub

Australian fauna is widely recognised for its high levels of endemism, and tardigrade fauna does not seem to be an exception in this respect. The richness of xerothermic habitats in Australia, often occupied by heterotardigrade family Echiniscidae, entails high abundance and uniqueness of echiniscid assemblages. A new gonochoristic/dioecious echiniscid species was found in large numbers in samples from Western Australia. Echiniscus siticulosus sp. nov., characterised by dominant large cuticular pores in the dorsal sculpture and appendages in the form of spines, represents the spinulosus group but can be distinguished from the known members of this species complex by a unique combination of traits: peculiar faceting of the caudal plate formed by ridge-shaped epicuticular extensions and pore morphology. An amended phenotypic diagnosis of Echiniscus spiniger Richters 1904, the species morphologically most similar to the new species, is also presented.