Barkdowners
The ultimate cat-dog otters

While a lineage of sheardogs, known as beasters, has evolved into bone-breaking predators and become the most successful mammalian apex predators of the continent, a smaller yet equally successful clade, the barkdowners, has pursued versatility.
Their body plan is a mixture of canine and feline features: their low stature and excellent climbing abilities give them a cat-like appearance, but their elongated skulls and teeth indicate dietary flexibility, akin to dogs. We are witnessing a true chimera: an otter attempting to adopt the best adaptations of both felids and canids. And they have succeeded, as barkdowners are now one of the most diverse predator groups in Antarctica, ranging in size from that of a fox to a leopard.

Due to their cat-like anatomy, barkdowners are not built for endurance running and prefer to ambush their prey. Shrubs and other abiotic elements of the environment play a crucial role in their hunting strategies, and their absence can severely limit the abundance of these carnivores. The smallest barkdowners, however, can navigate stealthily on the ground using the short grass of the trample steppe. Among these smaller species is the lone barkdowner (Dendricyon neopeninsularis), which rarely exceeds 10 kg.
As their name suggests, they are distributed along the Antarctic Peninsula, with more substantial populations on the warmer western coast. Their narrow skulls make them incapable of hunting large prey; instead, they specialize in hunting micromammals by stealthily approaching their dens or foraging areas. Their preferred prey includes young otterwatchers, ragos, vole-like species, and during times of scarcity, they may also consume plant matter such as berries, seeds, and carrion.
The species comprises several sub-populations, each with distinct behavioral adaptations to cope with their local environments: northern populations tend to create dens in trees and predominantly hunt arboreal species, while southern populations often seek refuge in abandoned underground tunnels or climb on large hollowed rocks and uniquely hunt terrestrial animals.

Among this otter group, the colossal barkdowner (Gigagracilis semiarborea) represents the upper size limit. Weighing in at 35-50 kg, comparable to a small to medium-sized tarsisnatcher, it is the only barkdowner species to exceed 20 kg. This elusive predator primarily inhabits shrubby and forested areas of the coldvanna, with only a few populations found in the trample steppe. Their limited range in the steppe is not due to a lack of shrubs or other hiding spots for hunting, but rather the high incidence of kleptoparasitism by other large carnivores, like beasters. It is no coincidence that this predator thrives in the steppe only where large rocks are present, providing opportunities to ambush prey and then retreat with the carcasses on top of these boulders, away from harassing carnivores. Alongside the two beaster species, the clam newnewotter, and two species of birds, the colossal barkdowner it's part of the Top 6 carnivore guild of Antarctica, thanks to their adaptations for hunting large herbivores. While their typical prey ranges from 20-100 kg, it is not uncommon to see colossal barkdowners taking down prey as large as an alphabetabrumble. Their diet, which primarily consists of large vertebrates, has driven significant anatomical changes, including a more robust anterior body and relatively shorter, stronger jaws reminiscent of beasters.