1. Chapter 5: Primates

2. Three types of primates
Prosimians (pre-monkeys)
Monkeys (Old World and New World)
Apes

3. Common Mammal Traits Fur (or body hair in Humans)
Long gestation & live birth (relative to other types of organisms)
Heterodontism (different kinds of specialized teeth)
Ability to maintain constant body temp (Homeothermy)
Increased brain size (greater ability for learning and behavioral flexibility)

4. Hands & Feet Great degree of Prehensility
Five digits on hands/feet (contra horses)
Opposable thumb
In most- divergent & partially opposable big toe
Nails on all or some digits
Highly sensitive tactile pads on digit ends

6. Question to Ponder
Why are Human Feet different?

7. II. Diet & Teeth
Lack of dietary specialization – most primates are generalized feeders eating a wide variety of foods
Therefore, primates have a generalized dentition

8. III. Senses & Brain
Vision enhanced
Olfaction reduced
Complex brain

9. Vision All primates rely heavily on vision
Color vision in Diurnal primates.
Stereoscopic vision
Eyes in front of skull, overlapping fields of vision
Accurate 3-D vision
Increased depth perception
Point to Ponder: Why would this be an adaptive trait? (hint: think environment)

10. V. Behaviors Tend to be diurnal Increased flexibility in behavior
Tend to live in social groups
In many primate social groups, males are permanent members – unusual among mammals.

11. Arboreal Adaptation Hypothesis
Traditionally, the arboreal adaptation seen as the primary factor in primate evolution
Selected for 3-D and color vision (why?).
Grasping prehensile hands/feet to grasp
Tropical arboreal environment = varied foods

12. Geographical Distribution

13. Most primates are arboreal, living in forest or woodland areas
Some Old World primates do spend considerable time on land.
No primate, except for humans, is fully terrestrial – all spend some time in trees.

14. Diet & Teeth Omnivorous w/generalized dentition
Although some primates prefer some food items over others, most eat a combo of fruit, leaves, and insects.
Some do eat meat (chimps & baboons)
Some are leaf specialists (Colobine monkey)

16. Teeth Most have 4 types of teeth
Incisors and canines: biting and cutting
Premolars and molars: crushing and grinding

17. Each Primate species has a specific dental pattern

18. Locomotion Almost all primates are quadrapedal
Many use more than one form of locomotion
Long, flexible lumbar spine which provides greater propulsion from hind legs

20. Two Suborders Prosimii Anthropoidea Lemurs, Lorises, Tarsiers
Monkeys, Apes, Humans

21. Prosimians: Lemurs & Lorises
Most primitive
Greater reliance on olfaction (long snouts)
Mark territory with scent
More laterally placed eyes
Shorter gestation & maturation
“dental comb” (projecting lower incisors & canines)

22. Lemur and Loris

23. Lemurs
Madagascar
Many different species (diversified in absence of competing primates)
Became extinct in other areas

24. Lemurs Range in size from 5”, 2 oz. to +2’, 22 lbs
Larger lemurs are diurnal, omnivorous
Smaller lemurs are nocturnal, insectivores
Many forms are arboreal, others are more terrestrial
Some live in large social groups
Others (Indri) are monogamous pairs

25. Lorises Similar in appearance to Lemurs
Tropical habitats (Sri Lanka, India, SE Asia, Africa)
Survived by adopting nocturnal habits
Competition avoidance with monkeys

26. Lorises Slow, cautious climbing form of quadrupedalism
Bushbabies active vertical climbers and leapers
Almost entirely insectivorous
Diet supplemented with fruit, gum, leaves

27. L & L Vision is stereoscopic, but less developed than anthropoids
Color vision in diurnal, but not nocturnal
Grooming claw on second toe (not fully nailed)
Longer life spans than similarly sized mammals

28. Tarsiers Nocturnal SE Asia Mated pair & offspring
Diet: insects & small vertebrates they catch by leaping from branches

29. Tarsiers difficult to classify
Prosimian traits:
Small size
Grooming claws
Unfused mandible
Anthropoid traits
Lack of Rhinarium (moist nose pad)
Orbits fully enclosed by bone

30. Anthropoids (monkeys, apes, H.s)
Generally larger body
Larger brains in absolute and relative size
Increased reliance on vision
Fully forward placed eyes; bony plate back of eye socket; greater degree of color vision
Fused mandibles; less specialized dentition
Female anatomy different; longer gestation; longer maturation; increased parental care
More social interaction

31. Monkeys ~ 70 % of all primates are monkeys Two types:
Old World or Catarrhini (downward-facing nose)
New World
Callitrichidae
Cebidae

32. New World Monkeys No fully opposable thumb.
Wide flaring noses with nostrils that face outward
Almost exclusively arboreal
Prehensile tails
No fully opposable thumb.
With one exception, diurnal
Two Groups:
Callitrichidae
Cebidae

33. Callitrichids
Small Marmosets and Tamarins

34. Marmosets and Tamarins
Most primitive monkeys
Retain claws instead of nails (used like squirrels to climb trees)
Twins rather than single births
Family groups
Mated pair
2 males & 1 female
Males very much involved in infant care

35. Cebids Larger than callitrichids 30 species
Diet varies with combo of fruits & leaves
Most are quadrupedals
Spider monkeys are semibrachiators

37. Old World Monkeys

38. Old World Monkeys and Apes
Nostrils are set close together and face downward.
Never have a prehensile tail,
Can have opposable thumb.

39. Still finding new monkeys
April 22, 2000: Conservation International announced the discovery 2 new marmoset species in the Amazon Basin of Brazil. 
Both species are squirrel size. 
They have been named Callithrix manicorensis and Callithrix acariensis. 
Since 1990, ten new monkey species have been discovered in Brazil. 

40. Hominoids (apes & humans)
Super-family includes:
Less apes: gibbons and siamangs
Great apes: gorillas, orangutans, chimps
Humans (family Hominidae)

41. Hominoid traits Lack of tail Larger body size (except in lesser apes)
Shortened trunk
Different musculature in shoulder joint
More complex behavior
Longer infant development & dependence
More complex brains

42. Hominoids