Simian

The simians (infraorder Simiiformes) are the "higher primates" familiar to most people: the Old World monkeys and apes, including humans, (together being the catarrhines), and the New World monkeys or platyrrhines. Simians tend to be larger than the "lower primates" or prosimians.

Classification and evolution
The simians are split into three groups. The New World monkeys in Platyrrhini parvorder split from the simian line about 40 million years ago (mya), leaving the Catarrhini parvorder occupying the Old World. This group split about 25 mya between the Old World monkeys and the apes. "Monkeys" are a paraphyletic group (i.e. not a single coherent group). Earlier classifications split the primates into two large groups: the "Prosimii" (strepsirrhines and tarsiers) and the simians in "Anthropoidea"(an'thro-poy'de-a)(Gr. anthropos, human).


 * ORDER PRIMATES
 * Suborder Strepsirrhini: non-tarsier prosimians
 * Suborder Anthropoidea (Haplorrhini): tarsiers, monkeys and apes
 * Infraorder Tarsiiformes
 * Infraorder Simiiformes
 * Parvorder Platyrrhini: New World monkeys
 * Family Cebidae: marmosets, tamarins, capuchins and squirrel monkeys
 * Family Aotidae: night or owl monkeys (douroucoulis)
 * Family Pitheciidae: titis, sakis and uakaris
 * Family Atelidae: howler, spider and woolly monkeys
 * Parvorder Catarrhini
 * Superfamily Cercopithecoidea
 * Family Cercopithecidae: Old World monkeys
 * Superfamily Hominoidea
 * Family Hylobatidae: gibbons
 * Family Hominidae: great apes and humans