Primates_2

Introduction to Primates

• Discusses the taxonomic approach to primate variation.

• Aimed at understanding the diversity of primates and their classifications.

Learning Outcomes

• Gain an appreciation of primate diversity.

• Describe the taxonomic groupings of primates and identify features used for classification.

• Classify a primate down to Superfamily or Family level.

Taxonomy of Primates

Order: Primates

• Suborder: Strepsirhini (strepsirhines)

  • Includes lemurs and lorises.

• Suborder: Haplorhini (haplorhines)

  • Splits into two infraorders:

    • Infraorder: Tarsiiformes (tarsiers)

    • Infraorder: Platyrrhini (New World monkeys)

    • Infraorder: Catarrhini (Old World monkeys and apes)

Superfamily Classification

• Superfamily: Lemuroidea (lemurs)

• Superfamily: Lorisoidea (lorises)

• Superfamily: Tarsioidea (tarsiers)

• Superfamily: Ceboidea (New World monkeys)

• Superfamily: Cercopithecoidea (Old World monkeys)

• Superfamily: Hominoidea (apes and humans)

Characteristics of Prosimans

Prosimii

• Earliest primate group, existing for over 55 million years.

• Features include:

  • Long snout, moist pad on nose (rhinarium) for scent marking.

  • Dental comb for grooming.

  • Unfused lower jaw (mandible).

  • Dental formula: 2-1-3-3/2-1-3-3.

  • Postorbital bar present instead of a plate.

  • Many are nocturnal with adaptations like tapetum lucidum for low-light vision.

  • Quadrupedal and primarily arboreal.

Lorisoidea

• Two families:

  • Lorises (Lorisidae)

  • Galagos (Galagidae)

• Characteristics:

  • Quadrupedal climbers, nocturnal, solitary.

  • Leave offspring in nests while foraging.

Lorisidae Examples

• Slow loris (Nycticebus coucang)

  • Found in SE Asia, weighs around 400g, known for being venomous.

• Slender loris (Loris tardigradus)

  • Weighs about 200g, has a slow and cryptic lifestyle.

Galagidae Examples

• Galagos or bush babies

  • Found in continental Africa, known for their long tails and large ears.

Lemuroidea

• Have a diversity of taxa primarily found in Madagascar.

• Most are nocturnal and arboreal, with some exhibiting torpor (decreased activity).

• Female dominance is noted in many species.

• Mouse lemur (Microcebus spp.) is the smallest primate.

Example: Lemur catta (Ring-tailed Lemur)

• Found in Madagascar, weighs about 3 kg, is diurnal and partly terrestrial.

• Notable for social behavior and scent-marking practices.

Tarsioidea

• Intermediate between Prosimii and Anthropoidea.

• Primarily found in East Asia, nocturnal, weighing about 110g.

• Unique traits:

  • Dental formula: 2-1-3-3/1-1-3-3.

  • Primarily animal prey diet, imperfect postorbital plate, and grooming claws.

  • Solitary with leaping locomotion.

Anthropoidea: Monkeys and Apes

General Characteristics

• Classification into New World and Old World monkeys and apes.

• Monophyletic group derived from a common ancestor.

• Characteristics:

  • No grooming claws, reliance on nails, lack of tapetum lucidum.

  • Generally diurnal, fused lower jaw, short snout, and increased brain size relative to prosimians.

Platyrrhini (New World Monkeys)

• Ceboidea:

  • Their unique prehensile tails allow for grasping.

  • Dental pattern: 2-1-3-3.

  • Arboreal living behaviors.

  • Two large families:

    • Cebidae: Includes diverse species like Capuchins and Spider monkeys.

    • Callitrichidae: Smaller size, includes Marmosets and Tamarins.

Catarrhini (Old World Monkeys)

Cercopithecoidea

• Consists of family Cercopithecidae, characterized by:

  • Dental formula: 2-1-2-3/2-1-2-3.

  • Bilophodont molars and ischial callosities.

  • Two subfamilies:

    • Cercopithecinae: Largely fruit eaters.

    • Colobinae: Leaf eaters with complex stomachs.

Hominoidea (Apes & Humans)

• Key features:

  • Larger body size, absence of tails.

  • Enhanced brachiation capabilities and flexibility in limb arrangement.

  • Y-5 molar structure and larger brains.

  • Prolonged dependency in young.

  • Classification distinction among subfamilies (Hylobatidae, Pongidae, Hominidae).

Hominoidea Example: Hominidae

• Includes Gorilla, Chimpanzees, and Bonobos with notable behavioral traits:

  • Knuckle walking and climbing abilities.

  • Chimpanzees are known for tool use, while bonobos exhibit unique social bonding behaviors.