Rails and coots of the middle Lentocene

Despite the monopolization of every large herbivorous niche by pygostylids (and partially by rostrids), rallids biodiversity is far superior. One monospecific radiation (the coose), was able to become extremely large, becoming the heaviest rallid ever known. While many species are still capable of flight, various separate lineages have become flightless, in favor of a more robust structure.

The descendant of the coose

If they were sapient, coose would be extremely thankful for this small ice age of the middle Lentocene. Red canelos (Winteridrimys sp.), the main plant food of the coose diet, find their optimal habitat in cold coastal forests, where thermal shocks and competition with other shrub species are lower. Two canelos hotspots can be found in Polarica, one in the D.D. and one in the Amery bay. This is where most of the global populations of Taurine coose (Taurofulica ddensis) can be found. This latest species of coose is far larger than its ancestor of 10 million years ago, weighing nearly twice. During the mild antarctic summer, the taurine coose live most of their day submerged, feeding on algae and canelo shrubs. They are good swimmers, still using the water to escape predators like their ancestors. Both sexes possess a forked red crest, used for social interaction: adults' crest has lighter colors, while juveniles maintain a dark red crest until sexual maturity. This helps to reduce useless internal conflicts. Thanks to their good swim capacity and the sea-level drop, Taurine coose have recently made their way to all large islands of Antarctica (Ellsworth, Marie Byrd, Weddell).

While coose were able to maintain a decent grade of gene flow thanks to their great dispersal rate, other rails were not able to do this, becoming endemic to singular islands. A good example of this is the genus Insurallus, all the members commonly known as Toka. The genus has originated in Polarica, and dispersed in the surrounding islands. From a singular species, now there are more than 7 species, all endemic to different islands, all flightless. They are omnivorous rails with a varied diet, that comprise invertebrates, eggs, fruits, seeds and sometimes fish.
In Marie Byrd, a different radiation of rails has produced the longtailed marierail (Marierallus caudatum), a carnivorous bird capable of hunting any small vertebrate on the island. They have strong legs, allowing them to fastly move in the austral forest. They are poor flyers, only using fly to move on tree branches, where they usually roost, away from larger ground predators.