The simians (infraorder Simiiformes) are the primates very common to most people: the monkeys and the apes, including humans. This clade is divided into the Platyrrhini (the New World monkeys) and the Catarrhini (the Old World monkeys, apes, and humans).

Classification and evolution

The simians are split into three groups. The first division is literally as wide as the Atlantic Ocean. The New World monkeys in clade Platyrrhini split from the simian line about 40 million years ago, leaving clade Catarrhini occupying the Old World. This group split about 25 mya between the Old World monkeys, and the apes.

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