A new freshwater mite of the marine genus Halacarellus (Acari: Halacaridae) from the Austrian Alps (Styria, Gesäuse National Park): Description and reflections on its origin

A new halacarid species, Halacarellus fontinalis n. sp., from a spring in the Gesäuse National Park, Austria is described. The species is characterised by three pairs of large, equal-sized Acetabula and slender claws and is expected to have evolved in the Tertiary from a Tethyan-Paratethyan Halacarellus species. Caspihalacarus Viets, 1928, with a single species, C. Hyrcanus Viets, 1928, has large and external Acetabula similar to those in H. fontinalis. Caspihalacarus is synonymised with Halacarellus.