Ratweasels

In the Early Muricene, many new species of rats tried their hand at becoming apex predators in their ecosystems. Today, though, one group has come to dominate all others, having driven all its competition to extinction as it took over all of Panapterra and Sub-Abeli. These are the ratweasels (genus Tondendens), descended from the Rattus acudens of northern Ailuropia, with small genetic contributions from other members of the unguivenator-pratidromaeus species complex due to ancient interbreeding events. They are most notable for how they dispatch their prey, using their incisors as a pair of shears. Their teeth are so sharp (and their masseters muscles so strong) that they have little difficulty chopping off a leg, tail, or even the head of their targets. They cannot cut through bone, so they must locate a joint before delivering their devastating bite. As such, their bodies have become long and flexible, allowing them to more easily position themselves during a fight. They range in size from the tiny Scurmint (T. saltitor), a small-animal-specialist that weighs no more than fifty grams, to the Sapbadger (T. ferox), a pack-hunting generalist that can weigh in at over ten kilos.

Ratweasels are most common across the rat-grasslands of Abeli, Sub-Abeli, and southern Loxodia. While highly effective against other rats and small kiwis, they struggle to match larger birds' speed and endurance. As such, ratite-dominated woodlouse-grasslands have their own set of avian predators that, in turn, find little success in ratweasel territory. Pseudoforests are a middle ground where all lineages have a chance of success, and many woodland-dwelling Tondendens species are adept ambush predators. On the open prairie, though, pursuit hunting is the only option. Ratweasels are capable of surprising bursts of speed; the Springspine (T. elasticus) can reach up to 30 kilometers an hour for about 30 seconds, barreling into prey that may outweigh it by a factor of five.

Once a kill is made, it can quickly be dismembered, after which the rat swallows each extremity whole. The body of the carcass, however, is more difficult; ratweasels often find it impossible to bite into the trunk of an animal after removing all the pieces that poke out. In some cases, they will simply abandon their kill after eating all the bits they can chop off, leaving the rest to be scavenged by other creatures. Others have learned to throw the corpse around until its entrails begin to spill out, allowing the hunter to glean a few more precious calories. Still others, such as the Stolecat (T. trullidens), have modified their teeth in a way that allows them to cut food into bite-sized chunks without losing their shearing abilities. The upper pair of incisors, when seen from the front, have a v-shaped gap between them, while the lower ones converge to a point in the middle, jutting out somewhat and allowing them to use a scooping motion to tear off pieces of meat. While the stolecat is a capable hunter, about 75% of its diet is composed of other ratweasels' abandoned food. It will even occasionally drive the rightful killer away from its freshly-killed prey, making off with whatever it can steal within a minute or two. Despite the actions of these scavengers, most ratweasel victims will eventually find themselves consumed by demestemimid woodlice.

Notably, one species in this genus displays clear semi-aquatic adaptations. T. lutromimus, the Fisherman Ratweasel, uses its long forelimbs to snag fish swimming in shallow water, then cuts them in half with one bite. While capable of swimming a modest distance, they rarely venture far from shore as they aren't capable of hunting in open waters. On occasion, though, they can get swept out to sea by the riptide currents that are common off Sub-Abeli's south coast. This has resulted in a fisherman-rat presence on several small islands, which they share with seawis and a few other species of swimming rats.