In the south of Abeli, there are two sizable landmasses separated from the mainland only by narrow straits, which in many points may be only a meter or two deep. Around the time of 22,000 PA, regular sea-level fluctuations led to a semi-permanent land bridge forming between these subcontinents and Abeli proper. The channel between the two islands has remained shallow to this day, filling with sediment nearly to the point of rising above the high-tide line. This means that terrestrial life can move between the two regions to this day. The waters that separate the Sub-Abelian archipelago from Panapterra still occasionally fall to traversable levels; for now, therefore, it is still considered part of the supercontinent. But that's not to say that its flora and fauna aren't already unique.
The plains of eastern Sub-Abeli have no basket-grasses or palm-grasses whatsoever. Instead, rat-grasses reign supreme here, composing upwards of 90% of all vegetative biomass on the subcontinent. Their mutualists are widely successful here too; seed-eating rats find ample food sources throughout these grasslands. Granivores are the dominant herbivores, with grazing species only just beginning to establish themselves. Rattus buccops has evolved to consume tremendous quantities of grain, digging burrows in which it stores massive piles of seeds. It can carry almost a third of its body weight within its large, flexible cheek cavities. This massive stockpile doesn't last as long as one might imagine, for its high metabolism means it must consume two-thirds of its body weight every day to survive. Luckily, winters are mild here, and modest amounts of food can still be found even in the coldest months. This fact does not prevent R. buccops individuals from raiding each other's nests. Not only will they pilfer as many seeds as they can fit in their mouths, but during times of scarcity, they will even consume other rats' pups. They incorporate no other meat in their eating habits, though, for they can extract ample protein from their otherwise herbivorous diet.
R. latifodiens, on the other hand, is a dedicated isopod-hunter. It roots through soil, rocks, and leaf litter to find its prey, often overturning dozens of square meters in a day's work. Its snout is long and narrow but attaches to powerful jaw muscles that allow it to crunch through the shell of even the toughest pill bug. While far from the largest rat in its environment, predators rarely come near it, for its long claws are as useful for cutting as for digging. It advertises its fierceness with a bright white stripe along its spine, a clear message that this rodent is not easy prey.
Piscivores have a presence here as well; a close cousin of R. platycauda migrated here not too long ago, and it has already diverged to form the new species Rattus velocignathus. Its jaws are triangular, pointed, and tipped with sharp, backward-pointing incisors capable of holding fast to a struggling Gambusia. It does not eat under the surface, instead dragging its quarry onto the shore. Here it can begin the hard work of tearing its prey apart with its hands (for its molars are still poorly adapted for processing flesh) while remaining close enough to the water that it can make an escape should a predator approach.
The most feared carnivore in the region is Rattus pratidromaeus, the larger sister species to the semi-aquatic R. unguivenator. An incredible long-distance runner, this species can sniff out a bleeding rat from over a mile away, arriving on the scene in time to dispatch its weakened prey. In fact, this species almost never preys on healthy individuals, seeking out exclusively sick, young, old, and injured targets. It can take down prey up to its own size, leaving few of its congenerics safe from its clutches.
R. fluviovenator, a much smaller hunter, is not a close relative of any other predatory murids. Instead, it has come to occupy a mesopredator niche independently of the unguivenator-pratidromaeus complex. While it often weighs in excess of a kilogram, it rarely hunts prey larger than a fifth its size. It digs smaller species out of their nests, feeding indiscriminately on young, old, sick, and healthy individuals. A poorly-hidden family of, say, R. micropes, will find all ten or so of its members quickly dispatched and dragged off to the hunter's own burrow, where it will feed on them for several days.
Rattus docicauda, a cousin of the aforementioned mouse-like prey species, is the smallest rat in the area. Its flexible, 30-gram frame is perfect for launching its body into the air, at which point its slender forelimbs grab madly at its airborne target. While its strategy may appear comical, it can catch over 100 mosquitoes in an hour during the intense spring mating flights of the local Ae. peripalustris, a large fly in the sedentarius subgenus. When winged prey becomes scarce, the flycatcher-rat returns to a more standard seed-eating lifestyle, a tried-and-true diet that will continue to support numerous rat species for many generations to come.