An insular success
The Boitomb carniere

With the sinking of the oceans, many Antarctic islands have reunited with the mainland, leading to the extinction of a lot of insular animal and plant species, in favor of the more competitive continental organisms.
Boitomb for example, despite being technically separate from the mainland, has a now continental wildlife association, due to the seasonal formation of an ice pack that unites this island with Neopolarica. 

Only one endemic insular species has managed to survive the continental invasion. Not only: the degree of specialization of this animal has allowed it to expand on the continent, even if only in the productive tramplesteppe; It is the Boitomb carniere (Falsimustela insularis)(plural: carnieri), the only survivor of a clade of terrestrial geotters that arrived in Boitomb a few million years after the END.
Unlike its ancestors, who were adapted to hunting terrestrial fauna, the Boitomb carniere usually feeds in coastal areas, where it mainly eats carcasses. The presence of large herbivores has done nothing but increase the number of carcasses present on the island, leading the species to a demographic explosion, followed by an expansion on the mainland.
The species has a very aggressive behavior, because of its habit of kleptoparasitizing the kills of large coastal birds: perhaps it was this behavioral trait that has graced this carnivore from the competition of other continental mesopredators.
Currently, the Boitomb carniere is widespread in the tramplesteppe of Ross hills, where it has not found much competition with other continental carnivores, especially due to the recent formation of this biome. Thanks to the abundant presence of megaherbivores, the range of this wotter is no longer confined to coastal habitats, but can also be found inland. 

The persistence of insular animals in continental environments is a rare but not impossible occurrence, especially for small animals on large islands*. For example, lagomorphs and (possibly) perissodactyls originated during the insular phase of India in the Paleogene.