Primates

Primates #

Why Study Primates? #

• Understand evolution as a species
• Use to model/understand evolutionary relationships
• Study origins of human traits

Placental Mammals #

• High energy usage
• Enhanced sensory reception
  • Bigger brains
  • Better flexibility/reaction
• High reproductive effort
  • Long lactation
  • Dependent offspring
  • Long gestation period

Primate Characteristics #

• Over 200 species
• Small, arboreal (live in trees)
• Most are monkeys or strepsirhines
• Orthograde Posture: erect, flexible limb structure
• Prehensility: hands and feet, opposable thumbs, tactile pads on hands
• Most are quadruped
  • Arboreal: longer legs + tails, brachiation: arm over arm swinging (primary locomotion for lesser apes)
  • Terrestrial: equal length arms + legs, short tail
  • Semi-brachiation: use tail
• Color vision (exception: nocturnal)
• Stereoscopic vision (depth)
• Decreased reliance on smell
• Types of heterodont dentition: (canines, incisors, premolar, molar)
• Diet: large variety (but not necessarily omnivorous)
  • Larger primates eat leaves, fruits
  • Smaller primates eat bugs, tree gum

Primate Habitats #

• Tropical climate
• Forest/woodland habitat
• Old World Monkeys: live on ground
  • Gorillas, chimps

Cladogram #

Strepsirhines #

Lemurs, Lorises #

• Nocturnal exc. lemurs
• Insectivores
• Arboreal
• Solitary living
• Reliant on olfaction, poor vision
• Southern Africa
  • Small
• Shiny, layered eyes

Haplorhines #

• Southern Africa
  • small
• shiny, layered eyes
• wet, sensitive nose
• VCL: vertical clinger and leapers
  • long legs, backs
  • powerful hands

Lorises #

• monogamous
• multiparous (lots of babies) - store young in trees
• Asian Lorises: slow moving, stalk prey

Lemurs #

• Madagascar
  • isolated, so adaptive radiation occurs
  • now many different types of lemurs

Atypical Strepsirhines #

• diurnal (awake in day)
• eat fruit (frugivorous), folivorous
• large social groups (ring-tailed lemurs)
  • dominance hierarchies (male-male competition)
• tails used to communicate
• diverse sizes
• Sifakas: bipedal, social
• Aye-ayes: solitary, unique feeding specialization

Cercopithecines #

• ectotympanic bony tube in ear
• rounded teeth, equal limbs, shorter tails, cheek pouches
• multimale polygamy, social hierarchy
• omnivorous, terrestrial
• colorful, big teeth → assert dominance to males
• baboons, mandrills, savannah baboons, hamadryas baboons, gelada baboons, macaques (snow monkeys)
• single male polygamous

Colobines #

• Colobus monkeys, odd-nosed monkeys
• folivorous, arboreal
• long legs + tails, complex stomachs, pointy teeth
• bilophodont molars

Must know species

Catarrhines #

• 2123 teeth (vs 2133 platyrhines)
• narrow noses
• downward facing nostrils
• Africa

Colobines #

• Langurs
  • very Asia, social, single male polygamy, infanticide on other groups to attract females over
  • folivorous → special stomachs
• Odd Nosed Monkey
  • very good swimmers
  • sexual dimorphism: nose size - changes pitch (for communication)
• Colobus Monkeys
  • black + white, red, other types
  • live in Africa
  • folivorous, eaten by chimps
  • single male polygamy

Tarsiers #

• SE Asia
• Nocturnal
• Clingers, Leapers
• solitary
• monogamous
• grooming claws
• unfused mandible (jaw)

Haplorhine Traits #

• free upper lip
• large upper incisors (no dental comb)
• enclosed eye sockets
• placenta: hemochorial (mother + baby close)
• babies are large
• ectotympanic tube in ear

Anthropoids #

• larger brain + body
• less reliance on smell, more on vision
• enclosed orbit eyes; stereoscopic color
• longer gestation, very high investment per baby
• fused mandible
• diurnal, social (active during day)
• includes humans and apes

New World Monkeys (Platyrrhines) #

3 groups:

• Atelids — flat-nose monkeys, spider monkeys

• Cebids — owl monkeys → leaf-eating frends

• Callitrichids — marmosets

• found in South America

• arboreal

• 2133 dental formula (humans 2123)

• larger ones eat fruit, leaves

• broad nose, outward nostrils

• semi-brachiation: hang w/ tail as 5th appendage; prehensile tails (not found in OWM)

• diurnal

• live in multi-male, multi-female large communities

• use tools (rocks open up food, etc)

Cebines #

• Capuchins
• Squirrel monkeys
  • big brains, communication
• Uakari monkeys
  • skin color used for communication; elusive
• Howler monkeys
  • loud noises for territory defense

Callitrichines #

• Tamarins, marmosets
  • give birth to twins
  • males care for offspring
  • polyandrous social structure: female mates w/ multiple males
  • gumivory, very small
  • territory defense of family

Old World Monkeys #

• catarrhines

• bilophodont molars (2 ridges)

• diurnal

• social

• quadrupedal (both ground and trees)

• larger than New World monkeys

• ischial callosities (bare, rough bottom for sitting on ground)

• sectorial premolar: sharpens canine above

• ring-shaped ear structure (OWM have bony tube)

• polyandrous social structure: female mates w/ multiple males

• gumivory, very small

• territory defense of family

Owl monkeys #

• only nocturnal haplorhine
  • (only other nocturnals are strepsirrhines)