The Primates

Key Questions• Where do humans fit in the world of living

things?

• What are the characteristics of primates?

• How are humans like the other primates? How are we unique?

Taxonomy• A classification system based on

similarities and differences• Phenetic Taxonomy = Following

Linnaeus, based on existing phenotypic features and adaptive behaviors

• Cladistics = Classification system based on order of evolutionary branching

Taxonomy of Humans & Chimps

Human Chimpanzee

Kingdom Animalia Animalia

Phylum Chordata Chordata

Class Mammalia Mammalia

Order Primates Primates

Family Hominidae Pongidae

Genus Homo Pan

Species Sapiens Troglodytes

Class Mammalia• Today, 19 Orders & over 4000 Species!

• 3 major subgroups: 1. Egg-laying (duck-billed platypus)2. Pouched (kangaroo, opossum)3. Placental

Exs. of Placental Orders other than Primates:Rodents (rats, squirrels, beavers)Carnivores (bears, dogs, cats)Insectivores (shrews, moles)Grazing-browsing (cows, hippos, deer, horses, sheep, goats)

Characteristics of Placental Mammals

1. Body hair

2. Relatively long gestation period followed by live birth

3. Ability to maintain constant internal body temperature = “warm-blooded”

Characteristics of Placental Mammals (cont.)

4. Increased brain size5. Mammary glands = origin of the

term “Mammal”6. Different types of teeth =

incisors, canines, premolars, molars

7. Considerable capacity for learning and behavioral flexibility

Primate Taxonomy

PRIMATES (order)

PROSIMIANS ANTHROPOIDEA (suborder)

Platyrrhini Catarrhini(flat nose) (downward nose)

Cercopithecoidea HOMINOIDEA

Lesser Apes Great Apes HOMINIDAE (family)

Prosimians New World Old World Gibbons Orangutan HUMANMonkeys Monkeys Siamangs Gorilla (species) Chimpanzee Bonobo

Prosimiansa. Fat-tailed galago

(mainland Africa)

b. Ruffed lemur (Madagascar)

c. Sifaka (Madagascar)

d. Ring-tailed lemur (Madagascar)

e. Mouse lemur (Madagascar)

f. Slow loris (South Asia)

g. Aye-aye (Islands off Madagascar)

Anthropoids a. Spider monkey (NW monkey)

b. Saki monkey (NW monkey)

c. Drill (OW terrestrial monkey)

d. Tamarin (NW marmoset)

e. Colobus (OW arboreal monkey)

f. Gibbon (OW lesser ape)

g. Gorilla (OW great ape)

Primate Characteristics:Hands & Feet

Enhancement of free mobility of the digits, especially of the thumb (opposability) and big toe

Both used for grasping = Prehensile Replacement of sharp, compressed claws by flat

nails; development of very sensitive tactile pads on the digits

Gripping Tool Use

Prehensile Tail

Primate Characteristics:Brain size & Smell

* Progressive shortening of the snout and reduction in the sense of smell

* Progressive expansion and elaboration of the brain, especially of the cerebral cortex

Primate Characteristics:Vision

Elaboration of the visual apparatus

Development of Stereoscopic Vision (3-D)

Bony sockets enclose eye nerves and muscles

Primate Characteristics: Dentition

* Retention of all tooth types

* Old World Anthropoid Dental Formula = 2.1.2.3 x 2=322.1.2.3

Primate Characteristics: Extended Gestation & Maturation

1. Primates are born at earlier stages of development than many other animals

2. Prolongation of postnatal life periods

3. Humans are born at a particularly early stage because of their larger brain; if born later, the baby’s head would be too large for the mother’s pelvis

Primate Characteristics:Body Stance

Progressive development of upright body stance leading to bipedalism

Primate Characteristics: Summary Large brains

3-D vision, Reduced Sense of Smell

Flexible shoulder joints, Vertical Positioning of Trunk

Hands and feet with five digits

Grasping thumb

Primate Characteristics: Summary (cont.) Flat fingernails instead of claws

Generalized dentition

Extended Gestation and Maturation

Strong Maternal-Offspring Bond

High Degree of Socialization

Primate Species 166 species currently identified

Most are tree dwellers

Most are herbivores (eat fruit or leaves)

Some are omnivores (eat anything)

Primate Distribution

Primate Classification

Primates are divided into two main Suborders:

1. Prosimians: Lemurs, Lorises,Tarsiers

2. Anthropoids: NW & OW Monkeys, Apes, Humans

Primate Taxonomy

PRIMATES (order)

PROSIMIANS ANTHROPOIDEA (suborder)

Platyrrhini Catarrhini(flat nose) (downward nose)

Cercopithecoidea HOMINOIDEA

Lesser Apes Great Apes HOMINIDAE

(family)Prosimians New World Old World Gibbons

Orangutan HUMANMonkeys Monkeys Siamangs Gorilla

(species) Chimpanzee Bonobo

Lemurs, Tarsiers, Aye-Ayes, Lori

Lemurs

Ringtail Lemurs

Lori

Aye-Aye

Aye-Aye The aye-aye shown here

lives on the island of Madagascar. It is a very specialized insect-eater.

Large eyes & good climbing abilities. The aye-aye, and most other prosimians, differ from monkeys and apes in having a moist area of skin on the nose.

Tarsier

Tarsier Large eyes, active at

night Like most of the

prosimians, good grasping ability & nails

Nails on all fingers and most toes, but there are specialized claws on the feet used for grooming called "toilet claws"

Tarsier

Platyrrhine Monkeys

Platyrrhines Flat noses Nostrils point

sideways Many have

prehensile tails

Live in South and Central America

Platyrrhine Noses

Platyrrhine Monkeys: Red-Howler & Spider Monkeys

Platyrrhine Monkeys: Capuchin Monkey

Platyrrhine Monkeys: Tamarins

Catarrhine Monkeys

Downward-pointing nostrils

Evolved and found in Africa and Asia

Catarrhine Nose

Catarrhines

Divided into two Superfamilies:

1. Old World Monkeys 2. Hominoids

Lack tails, have larger skulls, & walk partially upright

Include Gibbons, Gorillas, Orangutans, Humans, & Chimpanzees

Catarrhine Monkeys: Mandrill and Diana

Terrestrial Old World Monkeys: Baboon

Hominoid Taxonomy

Range of Hominoids

Lesser Ape: Gibbon

Great Ape: Orangutan

Great Ape: Gorilla

Gorillas: Knuckle Walking

Great Ape: Chimpanzee