The duck lineage is at the moment the most widespread and abundant group of antarctic anatids, living in both barren tundra and austral forest. They are extremely stocky animals, with various graviportal adaptations to sustain their weight on land (e.g., a proportionally short tarsus). They've also drastically reduced their wings, being 20% of their original size. 

Two separate species can be found on Polarica, with the largest being the anguck (Karenanas dentata), a gigantic duck that can exceed 60 kg (130 lb) in males. It's probably the most dangerous animal on the continent, due to its bad temper, attacking any large vertebrates that move unawares near them. They live in large herds of hundreds of individuals, with a strong migratory behavior. They are adapted to live in both tundra and austral forest, usually moving to the last one during winter.
Angucks have become extremely successful thanks to a simple modification of their digestive system: their gizzard is trichambered and with a rich microbiota that slows down food and helps destroy cellulose more efficiently. Essentially, it's a duck that has become a ruminant! It would be the first time for a duck and the second one for a bird to evolve this type of digestion; thanks to this adaptation, angucks can be found at higher densities compared to other anatids, due to an increase in the carrying capacity of their habitat. They are mixed feeders, eating any type of vegetation available.

A less successful duck lineage, but still pretty widespread, is the chickduck (Rinanas galliformis), so named because of its clumsy structure and triangular beak, like a chicken. It's a sedentary species that adapted to live only in open habitats (tundra and shrub tundra), eating grasses, herbs and sometimes large insects. Due to its smaller size compared to the anguck, the chickduck can fall prey to the large carnivores of Polarica, both terrestrial and aerial.

The hairy goose of 10 million years ago had great success after the appearance of the austral forest. One group was even able to become large-sized, losing completely their flying ability: the razorbills (Moanaloanser spp.), that comprise two species. Unlike the anguck, razorbills are pretty slim, being more agile. They are also socially different since they live mostly solitary or in couples. Due to duck competition, razorbills have become specialized feeders, eating leaves, mosses, lichens and barks from trees and shrubs of the austral forest.  No member of this genus is known to live in the tundra.

One species, the greater razorbill (Moanaloanser velox), is the tallest vertebrate in Antarctica, being able to eat leaves over 2 meters in height. It's a lightly built goose that can outspeed nearly any predator of Polarica; when threatened, it usually runs and hides in thickets, where they are safe from flying predators. Due to their size, land predators are usually not a threat to them.
Despite being flightless, wings are not vestigial but relatively elongated, since they are used for display or intimidating rivals. 

In the austral forest, the willow razorbill (Moanaloanser saliciphaga) can also be found. It's way smaller than its cousin, but it's much more widespread, moving also in shrub tundra. Its beak is unexpectedly strong, which helps it to break large seeds and cut large branches of willow, its favorite meal. Due to their small size, willow razorbills are more vulnerable to carnivores: if cornered, they often use their robust wings as a club to fight. During the reproductive period, they are known to prepare nests over large fallen trees, safe from predators.