20. Primates

Order Primates

  • General Overview

    • Comprises lemurs, monkeys, and apes

    • Encompasses 69 genera and 376 species

Suborder Strepsirrhini

  • Characteristics

    • Large eye sockets

    • Presence of a tooth comb

  • Distribution

    • Found in Oriental, Malaysian Peninsula, Ethiopian, and Neotropical regions

  • Evolutionary History

    • Dates back to 90 million years ago; oldest fossils located in North America

  • Physical Characteristics

    • Modified manus and pes for grasping (elongated and/or opposable pollex and hallux)

    • Arboreal traits present in most (e.g., prehensile tails)

    • Presence of claws and flat nails

    • Shortened rostrum and face, increased vision, decreased sense of smell, large brain, low reproductive rates, and increased social behavior

Infraorder Lemuriformes

Family Cheirogaleidae (Mouse or Dwarf Lemurs)

  • Composition: 5 genera, 21 species

  • Distribution: Madagascar

  • Characteristics:

    • Tooth comb formed from incisors and canines

    • Arboreal habits and small size

    • Feeding on flowers, nectar, insects, and small vertebrates

    • Dental formula: 2/3, 1/1, 2/2, 3/3 = 34

Family Lemuridae (True Lemurs)

  • Composition: 5 genera, 19 species

  • Distribution: Madagascar

  • Characteristics:

    • Similar tooth comb (incisors)

    • Mostly arboreal with one exception

    • Opposable pollex and hallux with slightly larger rostrum

    • Dental formula: 0-2/2, 1/1, 3/3, 3/3 = 32-36

Family Lepilemuridae (Sportive Lemurs)

  • Composition: 1 genus, 8 species

  • Distribution: Madagascar

  • Characteristics:

    • Lack upper incisors and have a unique jaw structure

    • Arboreal habits and enlarged caecum

    • Engage in coprophagy (eating feces for nutrients)

    • Dental formula: 0/2, 1/1, 3/3, 3/3 = 32

Family Indridae (Indrids)

  • Composition: 3 genera, 11 species

  • Distribution: Madagascar

  • Characteristics:

    • Tooth comb present (incisors)

    • Arboreal habits except for one species

    • Well-developed long limbs and tails

    • Shortened rostrum

    • Dental formula: 2/2, 1/0, 2/2, 3/3 = 30

Infraorder Chiromyiformes

  • Family Daubentoniidae (Aye-Aye)

    • Composition: 1 genus, 1 species

    • Distribution: Madagascar

    • Characteristics:

      • Highly enlarged incisors (mistaken for rodents)

      • Arboreal traits and elongated third finger

      • Dental formula: 1/1, 0-1/0, 1/0, 3/3 = 18-20

Infraorder Lorisiformes

Family Lorisidae (Lorids)

  • Composition: 5 genera, 9 species

  • Distribution: Ethiopia (south of Sahara) and Southeast Asia

  • Characteristics:

    • Lower canine resembling incisors

    • Arboreal climbers (hand-over-hand movement)

    • Dental formula: 1-2/2, 1/1, 3/3, 3/3 = 34-36

Family Galagonidae (Galagos)

  • Composition: 3 genera, 19 species

  • Distribution: Ethiopia

  • Characteristics:

    • With long limbs and powerful thighs for jumping

    • Unique long and sucker digits

    • Dental formula: 2/2, 1/1, 3/3, 3/3 = 36

Suborder Haplorrhini

Infraorder Tarsiiformes
Family Tarsiidae (Tarsiers)

  • Composition: 1 genus, 7 species

  • Distribution: Malaysia

  • Characteristics:

    • Large head with very large eyes

    • Disc-like pads on digits and elongated limbs

    • Dental formula: 2/1, 1/1, 3/3, 3/3 = 34

Infraorder Simiiformes
Parvorder Platyrrhini (New World Monkeys)

  • Characteristics:

    • Prehensile tails

    • Wide nostrils with upward tilt

Family Cebidae (New World Monkeys, Tamarins, and Marmosets)

  • Composition: 6 genera, 56 species

  • Distribution: Neotropics

  • Characteristics:

    • Elongated limbs, curved nails, and long prehensile tails

    • Chisel-shaped incisors and hallux has a nail

    • Presence of manes and tufts of hair around neck

    • Dental formula: 2/2, 1/1, 3/3, 2-3/2-3 = 32-36

Family Aotidae (Night Monkeys)

  • Composition: 1 genus, 8 species

  • Distribution: Neotropics

  • Characteristics:

    • Notable large eyes

Parvorder Catarrhini (Old World Monkeys)

  • Characteristics:

    • No prehensile tails

    • Nostrils are close together and have a downward tilt

Family Cercopithecidae (Tailed Apes)

  • Composition: 21 genera, 132 species

  • Distribution: Ethiopia, Oriental regions, and Malaysia

  • Characteristics:

    • All digits have nails, and most have tails

    • Dental formula: 2/2, 1/1, 2/2, 3/3 = 32

Family Hylobatidae (Gibbons)

  • Composition: 4 genera, 14 species

  • Distribution: Oriental

  • Characteristics:

    • Greatly elongated limbs and digits

    • Hands used as hooks and lack tails

    • Dental formula: 2/2, 1/1, 2/2, 3/3 = 32

Family Hominidae (Apes)

  • Composition: 4 genera, 7 species

  • Distribution: Ethiopian, Oriental, and Malaysian regions

  • Characteristics:

    • Robust skulls, bipedal locomotion (partially), and knuckle walking

    • Lack tails

    • Dental formula: 2/2, 1/1, 2/2, 3/3 = 32