WHY STUDY PRIMATES?
We share many aspects of our morphology, physiology and development with other primates
Homology: Traits similar because of common ancestry
• Wild chimpanzees
– make tools
– hunt animals
– live in male-bonded groups
– Captive chimpanzees can acquire basic human language skills
Analogy: Similar traits through convergent evolution
Baboons live in similar environments to early hominids, can illustrate potential food sources, selective
pressures acting on primates living in African woodlands and grasslands
Primate characteristics
Grasping hands and feet
thumb, big toe opposable
Fingers, toes with nails, not claws
Sense of smell reduced
Visual sense well-developed
Small litters, gestation & juvenile periods long
Unspecialized molars
Large brains
Primate Adult Dentition
Incisors--flat--used for nipping
Canines--slashing, shearing (in humans similar to incisors)
Premolars--puncturing, some grinding
Molars—Grinding
Humans have same dental formula as OW monkeys, apes
Modes of Primate Locomotion
Arboreal quadrupedalism
Terrestrial quadrupedalism
Vertical clinging and leaping
Brachiation
Bipedalism
Types of Primates
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, Suborder Strepsirrhini (The strepsirrhines)
• Lemurs in Madagascar, Lorises in Africa, SE Asia, Tarsiers in SE Asia
• Most “primitive” primates
– Relatively small brains
– Wet noses
– Greater reliance on smell
– Many nocturnal
– Many lack color vision
• Frugivores, folivores, plant gum and insects
• Some have “tooth comb” for grooming
• Postorbital bar but not closure
Suborder Haplorrhini (The haplorhines):
Tarsiers: Have adaptations like Prosimians, but may actually be more closely related to Anthropoids
SE Asia--Forest
Nocturnal insectivores, most carnivorous primate
Often monogamous
Have postorbital plate, fusion of frontal bone, and some other anthropoid characteristics
Infraorder Anthropoidea – New World Monkeys, Old World Monkeys, Apes, Humans
Platyrrhines (New World Monkeys)
True monkeys
Live in Central & South America
Some have prehensile tail
More arboreal than OW monkeys
Dental formulae either 2:1:3:3 or 2:1:3:2
Round, sideways oriented nostrils
Cercopithecoidea (Old World monkeys)
• Africa and Asia
• Generally larger than NW monkeys
• Narrow nostrils facing downwards
• 2:1:2:3 dental formula, bilophodont teeth (cusps organized into two rows)
• Broad array of habitats including dry, open settings
Hominoidea: Apes & Humans
-Orangutan, gibbons found in SE Asia
-Chimpanzee, bonobo & gorilla in Africa
-Humans most closely related to African apes
-2:1:2:3 dental formula w/o bilophodonty (molars not organized into rows) instead having a Y-5 cusp pattern
on mandibular molars
-No tails
-Larger, more complex brains than monkeys
-Shoulder blade on back, arm easily raised above head
2
We share many aspects of our morphology, physiology and development with other primates
Homology: Traits similar because of common ancestry
• Wild chimpanzees
– make tools
– hunt animals
– live in male-bonded groups
– Captive chimpanzees can acquire basic human language skills
Analogy: Similar traits through convergent evolution
Baboons live in similar environments to early hominids, can illustrate potential food sources, selective
pressures acting on primates living in African woodlands and grasslands
Primate characteristics
Grasping hands and feet
thumb, big toe opposable
Fingers, toes with nails, not claws
Sense of smell reduced
Visual sense well-developed
Small litters, gestation & juvenile periods long
Unspecialized molars
Large brains
Primate Adult Dentition
Incisors--flat--used for nipping
Canines--slashing, shearing (in humans similar to incisors)
Premolars--puncturing, some grinding
Molars—Grinding
Humans have same dental formula as OW monkeys, apes
Modes of Primate Locomotion
Arboreal quadrupedalism
Terrestrial quadrupedalism
Vertical clinging and leaping
Brachiation
Bipedalism
Types of Primates
1
, Suborder Strepsirrhini (The strepsirrhines)
• Lemurs in Madagascar, Lorises in Africa, SE Asia, Tarsiers in SE Asia
• Most “primitive” primates
– Relatively small brains
– Wet noses
– Greater reliance on smell
– Many nocturnal
– Many lack color vision
• Frugivores, folivores, plant gum and insects
• Some have “tooth comb” for grooming
• Postorbital bar but not closure
Suborder Haplorrhini (The haplorhines):
Tarsiers: Have adaptations like Prosimians, but may actually be more closely related to Anthropoids
SE Asia--Forest
Nocturnal insectivores, most carnivorous primate
Often monogamous
Have postorbital plate, fusion of frontal bone, and some other anthropoid characteristics
Infraorder Anthropoidea – New World Monkeys, Old World Monkeys, Apes, Humans
Platyrrhines (New World Monkeys)
True monkeys
Live in Central & South America
Some have prehensile tail
More arboreal than OW monkeys
Dental formulae either 2:1:3:3 or 2:1:3:2
Round, sideways oriented nostrils
Cercopithecoidea (Old World monkeys)
• Africa and Asia
• Generally larger than NW monkeys
• Narrow nostrils facing downwards
• 2:1:2:3 dental formula, bilophodont teeth (cusps organized into two rows)
• Broad array of habitats including dry, open settings
Hominoidea: Apes & Humans
-Orangutan, gibbons found in SE Asia
-Chimpanzee, bonobo & gorilla in Africa
-Humans most closely related to African apes
-2:1:2:3 dental formula w/o bilophodonty (molars not organized into rows) instead having a Y-5 cusp pattern
on mandibular molars
-No tails
-Larger, more complex brains than monkeys
-Shoulder blade on back, arm easily raised above head
2
