The largest species are in the genus Carnopapio. The largest species, C. grandis, stands an amazing 9 feet tall. Though they do not hesitate to hunt some small animals, they mostly scavenge the kills of other larger predators. Particularly those of Castosarchus. In fact, Carnopapio always lives in close proximity to Castosarchus territories. Since Castosarchus chiefly feeds on large antelopes, there is always plenty for the Carnopapio monkeys to scavenge. Carnopapio is also bipedal, and walk around in very bird-like fashion. This gives them an advantage over most other scavengers, since they are better able to see over the tall grass of their habitat. Carnopapio lives in large groups, usually 10-15 strong.
The smallest of these monkeys is in the genus Colobonyx. These are tiny monkeys, which spend almost 100% of their time in the trees. At night, they usually find a hollow to huddle in. During the day, they scamper through the trees, able to make 20-foot jumps from one tree to another. They feed primarily on insects and fruits. Their groups are rather large too, usually numbering up to 50 individuals. Females dominate their society. These little monkeys move much like modern monkeys do, using their hind legs to push them off the branches, and gripping the landing spot with their bare pads and long claws. The tail is not prehensile, and usually held upward while the monkeys are in motion. The tail is brightly colored, and most vivid in the higher ranking animals in their group.
The most unusual monkey in this group is in the genus Alesimia, which has a long, flexible gliding membrane that unfolds when the monkey leaps, much like today's flying squirrels. Also like flying squirrels, these monkeys have flat tails and they are capable of flattening out their body, to make it easier to glide and to go much further than the average monkey can with just their legs. These monkeys live in smaller groups, usually small family groups. Their glides can carry these monkeys as far as 200 feet in a single bound. Their sharp, curved claws make landing and clinging to the tree trunks they typically land on, a breeze.
The most carnivorous member of this family is Dryptopithecus. These monkeys do not favor leaping from one branch to another, they prefer to use brachiation, like modern gibbons, when moving through the trees. Their long arms aid them in moving gracefully through the tree branches. They hunt down rather large prey, up to the size of Armasenex. They kill their prey by eating them alive. Up to 5 adults typically go out hunting game, bringing morsels home to their family, which may be waiting in nearby branches. The hunting party is led by the dominant male and female, with beta males and females lagging behind. They close in when their prey is spotted, usually with one member of the hunting team first attacking and subduing the prey from behind, and the rest of the hunting team closing in to tear the prey apart. Unlike modern hunting primates like chimpanzees and baboons, these monkeys are quiet hunters, barely making a sound when stalking their prey. They communicate most notably during a hunt, with series of short clicks that somewhat resembles morse code.
Like modern monkeys, these animals have a whole host of predators. Some of the biggest are the larger viverrids and deinognathids, such as Spathodon and Elaphictis. But they can also fall prey to larger snakes, crocodiles, predatory bats, and even monitor lizards. Because most of these monkeys live in groups, one individual is usually assigned the duty of keeping watch for predators as the rest of the groups feed, or relax. It is not always the same individual, as with all other animal groups. But it is usually given to a lower-ranking member that is still very alert and quick to react.