Evidence for Cryptic Diversity in the "Pan-Antarctic" Springtail and the Description of Two New Species.

The invertebrate terrestrial fauna of Antarctica is being investigated with increasing interest to discover how life interacts with the extreme polar environment and how millions of years of evolution have shaped their biodiversity. Classical taxonomic approaches, complemented by molecular tools, are improving our understanding of the systematic relationships of some species, changing the nomenclature of taxa and challenging the taxonomic status of others. The springtail has previously been described as the only species with a "pan-Antarctic" distribution. However, recent genetic comparisons have pointed to another scenario. The latest morphological study has confined to the sub-Antarctic island of South Georgia, from which it was originally described, and resurrected as a congeneric species occurring on the continental mainland. Molecular data demonstrate that populations of this taxon, ostensibly occurring across Maritime and Continental Antarctica, as well as on some offshore islands, are evolutionarily isolated and divergent and cannot be included within a single species. The present study, combining morphological with molecular data, attempts to validate this hypothesis and challenges the taxonomic status of suggesting that two additional new species, described here as sp. nov. and sp. nov., are present in Continental Antarctica.