The discovery of a primitive arthropod species inside a limestone cave on Vancouver Island in Canada has raised questions among scientists about its origin.
Until deglaciation began some 18,000 years ago, the island itself and its caves were covered by a thick sheet of ice.
The previously-unknown species, named the Haplocampa wagnelli, has an elongated and slender - a 'trademark' feature for strictly underground arthropods.
Cavers Craig Wagnell, Tawney Lem and Felix Ossigi-Bonanno from the Central Island Caving Club along with Alberto Sendra from the Alcala University in Spain, found the creature in a cave recently unearthed in the small limestone area on Vancouver Island.
Its presence in the caves presented proves either terrestrial arthropods survived in deep subterranean habitats during the Last Glacial Maximum, which peaked around 26,000 years ago.
The scientists note close relationships between the genus of the new species and three others known from the two sides of the north Pacific Ocean - Japanese Islands and the Korean Peninsula.
This led to another possibility could be that they separated from their Asian relatives and migrated to Vancouver Island during deglaciation.
It has only slightly elongated antennae and its legs and abdomen are shorter and thicker than most of its relatives.
This shape suggests the species doesn't live exclusively underground and is likely found in soil habitats above ground leading researchers to conclude that the species is not exclusively subterranean and is likely to also be present in soil habitats.
On the other hand, its North American sister species seem to be even less adapted to life underground.
The Haplocampa wagnelli is most closely related to three species, two of which are found on the other side of the Pacific, in Japan and Siberia.
Its unique similarities to both Asian and North American hexapods 'suggest probable dispersal events over the Bering Land Bridge,' the researchers wrote.
Furthermore, the new species is also one of the most northerly cave-adapted dipluran species, found at a latitude of 49º north.
26,500 years ago, its modern habitat would have been located underneath the Cordilleran Ice Sheet, part of the Late Wisconsinan North American ice sheet complex, according to the study.
The full findings of the study were published in the journal Subterranean Biology.
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