Wotters to the rescue

Thanks to its great size and habitat diversity, Polarica is the wotter stronghold: Belgrano wetlowland possesses the richest wotter assemblage, where the most diverging clades can be found.
Some genera have retained a discrete degree of omnivory, like squirrel wotters (Sciuricyon sp.), which ordinarily feed on fruits, leaves, seeds, invertebrates and small birds. Some species have become snail-specialists, the largest inland invertebrates of Antarctica, which are killed by crushing their shell with their durophagous teeth. They are one of the smallest geotters in the continent, rarely exceeding one kg of weight.
The vernacular name "squirrel wotter" derives from their resemblance to squirrels, mostly due to their hairy tail and excellent arboreal abilities. They are capable of using their tail as a rudimentary parachute, "gliding" from tree to tree while escaping from predators.

The largest mainland wotters are the mouchers (Ursilutra sp.), the most derived wotter genus: unlike other wotters, which possess bunodont molars, mouchers have hypsodont teeth: this adaptation increases the mastication efficiency of plant matter, which comprise more than 80% of their diet.
Cellulose digestion is still very inefficient compared to rostrids and ducktails, with just a long intestine with poor bacterial flora. Due to this, mouchers tend to eat highly energetic food, like fruits and seeds.
Supplementary food includes beetles extracted from deadwood using their strong claws, which also act as a good defense. The largest species is the greater moucher (Ursilutra ipsodonta), which can attain the size of a fox.