Subglacial refugia in Iceland enabled groundwater amphipods to survive glaciations

An endemic family of subterranean amphipods (Crustacea) has recently been discovered in Iceland, in addition to a new species of a previously known amphipod family. These findings are remarkable because Iceland was covered by glaciers from about 2.6 million BP to about 10,000 BP and is isolated on the mid-Atlantic Ridge, far from the North American and European continents. We argue that there were subglacial refugia in Iceland during the Quaternary glacial period. The presence of subterranean amphipods, belonging to an old group with its present distribution mainly in North America and the Eurasian continent, indicates past contact of subterranean fresh waters of Iceland and the North Atlantic continent. The amphipods currently found in Iceland may have been present in Greenland at 40 Ma, when the precursor of Iceland drifted together with the hot spot (Iceland plume) from Greenland.