Ragos
Giants and dwarfs

Wotters, like the first otter that colonized Antarctica, have maintained a proportionally huge bite force, which is used to better chew invertebrates, leaves and fruits.
With the rise of the (nearly) herbivores ragos, the masticatory system increased further in complexity, developing deep-crowned teeth with short roots (hypsodont dentition). The digestive system however is poorly developed, comparable to a bear, limiting the energetic gain from food. Due to this, ragos must consume plant biomass two or three times higher than a rostrid in order to assume the same number of calories. 

One solution to overcome these energetic issues is often gigantism: the larger you are, the lesser food you need proportionally to maintain your metabolism. That's why some species of ragos have become bear-sized, like the titarago (Lutrursus longilinues) the largest antarctic vertebrate of the late Cambiocene.
This species can be found in the entire sub-tropical forests of Neopolarica, in both pluvial and mediterranean biomes.
With fruits and seeds comprising even 70% of their diet, this giant can be labelled as a frugivore, integrating sometimes its diet with grass, leaves and insects.
Like all giant ragos, titaragos seek refuge in the thickets of their territory, where the undergrowth is richer of fruity plants. While adults are obbligate terrestrial animals, youngs can easily escape from predators, search for food or just play by climbing on trees like all ancestral wotters.
Cubs are raised by both parents, which form monogamous pairs for life; after reaching 4-5 years, young titaragos leave their parents in order to find a partner and colonize new territories.
Titaragos' couples have immense home ranges because of their necessity of eating a lot of food, ranging from 30 to 200 km2. Due to this, titaragos have little impact on the botanical composition of their environments, compared to the triumvirate.

Other ragos have maintained a modest size, like furagos (genus Peligeneta), marten-sized species that dwell as south as the austral forests of the Transantarctic Mountains: by adapting to colder and poorer environments, furragos has partially reverted its diet to omnivory: plant matter still comprises over 65% of their diet, but another significant part (10-20%) include rodents and insects, which are usually eaten during summer and autumn, when their densities are higher. When temperatures drop below 0°C, furagos are capable of hibernating. This is the first time that a wotter evolve a prologned torpor, which can last even 4 months.