Characteristics
 

1)  diurnal 2)  fruit eaters 3)  flat incisors 4)  2:1:2:3 dentition (generally) 5)  flat noses

6)   vision oriented 7)   fully bony eye socket 8)   arboreal 9)   sit on haunches 10) prehensile tails (only 5)

I.  Callithricids
    a. marmosets and tamarins
    b. small
    c. eat exudates
    d. hooked nails
        1.  look like claws but are only one layer
    e. some have multiple births
    f. 2:1:3:2 dentition
        1.  somewhere along the line lost a molar

II. Cebids
    a. small diverse monkeys
    b. prehensile tails (only five monkeys)
        1. capucchin monkey
        2. howler monkey
        3. wooly monkey
        4. spider monkey
        5. wooly spider monkey

(the rest of the group includes night monkeys, titi monkeys, squirrel monkeys, sakis/uacaris, and howler monkeys)