#apochela

Bergtrollus dzimbowski is the only species is the genus Bergtrollus. The name Bergtrollus is named after the mythical Scandinavian "mountain troll".

Tardigrades of the genus Milnesium are famous for being one of the most desiccation and radiation-resistant invertebrates on Earth, due to their unique ability to transform into a "tun" state and utilize intrinsically disordered proteins when experiencing extreme environments. In 2007, individuals of two tardigrade species, Richtersius coronifer and Milnesium tardigradum (image 1), were subject to the radiation, near-vacuum, and near-absolute zero conditions of outer space as part of the European Space Agency's Biopan-6 experiment. Three specimens of Milnesium tardigradum survived, while the Richtersius coronifer did not. M. tardigradum can survive high amount of environmental stress by initiating cryptobiosis. During this state, the internal organic clock of M. tardigradum halts, thus, the tardigrade does not even age during this time.

Milnesium tardigradum was voted the winner of The Guardian's "2025 invertebrate of the year" competition, from a shortlist of ten. The article describing the conclusion of the contest stated that the species had "endured all five previous planetary extinction events" (which is not necessarily true, M. tardigradum is a recent species, and the genus Milnesium is from the Cretaceous and thus endured only one planetary extinction event. The phylum Tardigrada as a whole has stem ancestors in the Cambrian, so perhaps they are attributing the successes of the entire phylum to this one species!)

Milnesium tardigradum is one of the largest species of tardigrades, at up to 1.4 mm long.