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 A105 Human Origins and Prehistory
Lecture 5

Classification of Modern Nonhuman Primates; Primate Traits

We had an activity on primate classification; accepted classifications for all the primates you looked at are posted in the Activity section of the website, as well as the classification presented in class.

I. Classifying Modern Primates -- From Prosimians to People
      A. Helpful Terms 

            Prosimian – implies similar to monkeys. 

            Anthropoid – literally means humanlike. 

           Primitive -- means similar to ancestral forms.

           Derived -- means different from ancestral forms.
     The last two terms above are comparative terms; an animal would, for instance, be primitive with respect to its descendants but derived with respect to its ancestors.

     The Two Suborders
          Prosimii, containing lemurs, lorises, and tarsiers (and their ancestors); 
      Anthropoidea, containing monkeys, apes, and humans (and their ancestors). 

An Alternative Division
Some scientists would place the tarsier with the monkeys and apes. This gives:
Strepsirhini, including lemurs and lorises; 
Catarrhini, including tarsiers, monkeys, apes, and humans. 
We will follow the classification given in your book.

                                  Prosimii (Prosimians) 
Lemurs (superfamily includes indri, sifaka, and aye-aye) 
Lorises (superfamily includes slow lorises and galago/bush baby) 
Tarsier 

                              Anthropoidea (Monkeys and Apes) 
Old World Monkeys (vervets, macaques, baboons; Africa, Asia, Europe)
New World Monkeys (capuchin, marmosets, tamarins, spider monkey, howler) 
Apes (orangutan, gibbon, siamang in Asia; chimp, gorilla, bonobo in Africa)
Hominids (the human “family”) 

In the following list of primate characteristics, you should know the characteristics listed for the larger groups (prosimians, anthropoids, Old and New World monkeys, etc.).  I have boldfaced the traits that are most important for the smaller groups (lemurs, lorises, etc.).  Some of this will be review from the film, Life in the Trees.

Prosimian Characteristics

They are the most primitive primates. 
Small body size, smaller brains. 
Rely less on sight than other primates, more on smell. 
Mature quickly compared with anthropoids; live shorter lives. 
Vertical clinging and leaping (VCL) -- not all prosimians use it, but VCL is still a hallmark of the group (monkeys and apes do not use it). 

          Lemurs (Lemuroidea)
          Confined to Madagascar
          22 species 
          Tooth comb, wet nose, small (20 lbs. or less) 
          Postorbital bar, but not closure 
          Lemurs are smaller, generalized quadruped. 
          Indri, sifaka are larger, VCL. 

         Lorises (Lorisoidea)
         Tropical (SE Asia, India, Africa) 
         Nocturnal, 13 species 
         On average, smaller than lemurs (3 lb. or less) 
         Short lived 
         Two kinds: slow (loris) and fast (galago). 
         Loris slow climber, galago VCL 

        Tarsiers (Tarsiioidea)
        Island SE Asia (Philippines, etc.) 
        “Intermediates” 
        Derived: Nose not wet, closed eye sockets, single births, reproductive 
                       biology 
        Primitive: Nocturnal, very small (up to ½ lb.), VCL, insectivore 
        A mix of primitive and derived characteristics. 

                               Anthropoids
Different from Prosimians in: 
Shorter faces (no snout) 
Larger brains 
Better vision; more postures freeing hands 
Tend to live longer, have single births. 

Three superfamilies -- New World Primates, Old World Monkeys, Apes.

        New World Primates (All are Monkeys); Infraorder Platyrrhini
45-50 species, Central and South America
Diurnal except for one genus; all arboreal; some with prehensile tails
Wide noses with flaring nostrils
3 Groups in 2 Families

                 Group 1: "Mini Monkeys"; Family Callitrichidae
                 Marmosets and tamarins; the most primitive monkeys.
                 Claws, twin births, maturation timetable like prosimians.
                 Eat insects, some tree gums, fruit
                 Social systems: Pair bonded, sometimes polyandrous

               "Regular" New World Monkeys; Family Cebidae
               About 30 species; live in large groups
               Slow maturing, live up to 40 years, single births; varied diets
              Group 2: Generalized quadrupedal locomotion. Capuchin, squirrel 
                              monkey.
              Group 3: Suspensory locomotion.Grasping tail.  Howler monkey, 
                             spider monkey, muriqui.

          Old World Primates (Monkeys and Apes); Infraorder Catarrhini

Old World Monkeys, Superfamily Cercopithecoidea
About 70 species; live in Africa, S. Asia, India, Japan
No prehensile tails; some are partially terrestrial. All diurnal.
Larger on average than New World monkeys -- 5-75 lbs.
Live up to 35 years; single births; some show sexual dimorphism.

    Leaf Monkeys -- Main food is leaves.  Most are Asian, a few African species.  Live in small groups with 1-2 adult males.  Colobus is generic name.

    Generalized Monkeys -- Omnivores.  Most live in Africa.  Macaques, baboons, guenons.  Live in large groups.  Macaques the most widely distributed nonhuman primate -- Africa to Japan.

Apes and Humans, Superfamily Hominoidea
Live in Africa, SE Asia (global distribution in case of humans)
15-300+ lbs; mature 10-15 years; live up to 40 (60 in captivity)
No tails, short trunk with wide chest, mobile shoulders with long arms
Complex brains, long infant dependency.

    Gibbons, Family Hylobatidae -- Gibbons and siamangs.  Pair bonded, little dimorphism; eat fruit, some leaves, flowers, insects. Brachiation.  Live SE Asia.

    Orangutan, Family Pongidae -- Two subspecies, one on Borneo, one on Sumatra (SE Asian islands).  Highly mobile joints; mostly frugivorous.  Fist-walking when on the ground. "Four-handed" locomotion. Arboreal. Solitary. Pongo pygmaeus.

    Gorilla, Family Pongidae -- African forest dwellers, two main groups (mountain and lowlands).  The largest primate; folivorous; terrestrial with knuckle-walking; groups have one male, several females, babies. Gorilla gorilla.

    Chimpanzee, Family Pongidae -- African forests.   Smaller than gorilla; less dimorphic.  Quadrupedal (knuckle-walking) on ground, suspensory in trees.  Omnivorous.  Up to 50 in groups; highly complex social organization.  Pan troglodytes.

    Bonobo, Family Pongidae -- Only in Congo, south of Congo River.  Diet similar to chimp.  Not smaller than chimp, but more slender.  Relationships develop among all combinations of group memebers; less aggression than in chimps.  Very frequent copulation.  Locomotion like chimp, but more frequently stand on two legs.  Pan paniscus.