Exceptional tardigrade-dominated ecosystems in Ellsworth Land, Antarctica

We describe a terrestrial faunal community including only Tardigrada and Rotifera, present on inland nunataks of Ellsworth Land, Antarctica (∼75°–77° S, 70°–73° W). The fauna is exceptional in its simplicity, including five tardigrade species (three new to science) and at least two rotifer species, which comprise two consumer trophic levels. Nematode worms, the most important element of the simplest faunal communities previously reported worldwide (from the Ross Sea Dry Valley region of continental Antarctica), and microarthropods, otherwise represented in all known Antarctic terrestrial communities, are absent. The tardigrade community composition shows affinity with the continental Antarctic fauna, with which it shares three species. The remaining two species are unique to Ellsworth Land and may suggest a prolonged existence as a distinct biogeographical unit.