...so that leaves only the other forms of primates:
<snip>
Primates
The mammalian order to which humans belong. Primates are generally arboreal mammals with a geographic distribution largely restricted to the Tropics. Unlike most other mammalian orders, the primates cannot be defined by a diagnostic suite of specializations, but are characterized by a combination of primitive features and progressive trends. These include:
Increased dominance of vision over olfaction, with eyes more frontally directed, development of stereoscopic vision, and reduction in the length of the snout.
Eye sockets of the skull completely encircled by bone.
Loss of an incisor and premolar from each half of the upper and lower jaws with respect to primitive placental mammals.
Increased size and complexity of the brain, especially those centers involving vision, memory, and learning.
Development of grasping hands and feet, with a tendency to use the hands rather than the snout as the primary exploratory and manipulative organ.
Progressive elaboration of the placenta in conjunction with longer gestation period, small litter size (only one or two infants), and precocial young.
Increased period of infant dependency and more intensive parenting.
A tendency to live in complex, long-lasting social groups.
It has been recognized for a long time that many of these features are adaptations for living in trees. However, it has been proposed more recently that primates may have developed their specializations as a consequence of being visually directed predators, living among the smaller branches of the forest canopy or undergrowth, that captured insects with their hands.
Classification of the primates is as follows:
Order Primates
Suborder Strepsirhini
Infraorder Lorisiformes
Superfamily Lorisoidea
Family: Lorisidae (lorises)
Galagidae (bushbabies)
Infraorder Lemuriformes
Superfamily Lemuroidea
Family: Cheirogaleidae (dwarf lemurs)
Lepilemuridae (sportive lemur)
Lemuridae (true lemurs)
Indriidae (sifakas, indri, woolly lemur)
Daubentoniidae (aye-aye)
Suborder Haplorhini
Hyporder Tarsiiformes
Superfamily Tarsioidea
Family Tarsiidae (tarsiers)
Hyporder Anthropoidea
Infraorder Platyrrhini
Superfamily Ceboidea
Family: Callitrichidae (marmosets, tamarins)
Cebidae (capuchins, squirrel monkeys, douroucoulis, titis)
Atelidae (sakis, uakaris, howler monkeys, spider monkeys, woolly monkeys)
Infraorder Catarrhini
Superfamily Cercopithecoidea
Family Cercopithecidae (Old World monkeys)
Superfamily Hominoidea
Family: Hylobatidae (gibbons, siamang)
Hominidae (orangutan, gorilla, chimpanzees, humans)
There are two major groups of primates: the strepsirhines or “lower” primates, and the haplorhines or “higher” primates. Strepsirhines have elongated and forwardly projecting lower front teeth that form a toothcomb, used for grooming the fur and for obtaining resins and gums from trees as a source of food. The digits of the hands and feet bear flattened nails, rather than claws, except for the second toe, which retains a sharp toilet claw for grooming. They also have a moist, naked rhinarium and cleft upper lip (similar to the wet noses of dogs). Most strepsirhines are nocturnal, with large eyes and a special reflective layer (the tapetum lucidum) behind the retina that intensifies images in low light. Compared with haplorhines, the brain size is relatively small and the snout tends to be longer.
The strepsirhines are subdivided into two major groups: the lorisoids, which are found throughout tropical Africa and Asia, and the lemuroids, which are restricted to Madagascar.
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