The painted repandor is a canithere tribbethere from Dylan Bajda's Serina, that lives during the Ultimocene period.
The repandors, clade Repandorsatheria, are the more derived and currently more specious canithere group on Serina, which comprise four genera. Their clade name (literally "upward-curving-backed beast") accounts for their extraordinarily flexible backs which curve dramatically during locomotion, serving as a spring to store and release energy and allow for rapid movement over land in pursuit of prey.
While repandors have specialized further toward high speed and so have considerably longer legs and leaner bodies than the first tribbetheres, they are the nonetheless fairly primitive. Indeed, the wider canithere clade [including its aquatic derivatives] is the only one among tribbetheria which has remained almost entirely carnivorous and the extant terrestrial representatives, despite their specializations, still retain the least divergent ancestral traits of all their clade. The extensible jaw typical of basal tribbetheres is present in all canitheres, but while the first species of the Pangeacene and their single modern representative had powerfully built crushing jaws and were capable of preying on relatively large animals, the modern repandors have moved away from this toward a precise snapping jaw well-suited to snatch up smaller vertebrate prey. This is a direct example of ecological niche partitioning which began to occur as a younger tribbethere clade - the circuagodonts - displaced both the stronger carnivorous canitheres which formerly hunted the flocks of serezelles and other placental birds, and much of these former prey species themselves, toward the end of the Pangeacene.
In addition to their more flexible spines, thinner build, and elongated limbs, the repandors are distinct from their predecessors in having evolved lengthier, narrower snapping jaws adapted to grasp, hold, and render into small portions whole vertebrate prey in a manner unique among land predators. When the jaw is closed and retracted this gives them an even more canine profile, with a long face like a collie, an impression furthered by the large, mobile ears which express emotion. As the jaws open up though the impression breaks down rapidly as the jaws expand first outward, then forward like a shark's, with the lower jaw in particular projecting down and ahead to grasp small fleeing prey and snap it against the needle-like fang teeth on the upper jaw. The bite force at the front of the jaws is not powerful, and though it holds the prey securely it rarely kills it outright. Instead, the final blow is delivered by the more powerful back of the mouth as the jaws retract back into place. While more basal canitheres could chew by shearing their rear molars together, the repandor uses this to kill. As the jaw retracts, the prey is pulled back into the mouth and between six razor-like slicing teeth in the rear of both jaws which then occlude together in a shearing motion, cutting the victim apart into several smaller portions that are then easily swallowed.
Gallery[]
The repandor's jaws, like those of its teleost fish ancestors, are able to extend outward when biting or swallowing prey.
Animation of a repandor running.