The Anthropoids (page 365)
The Anthropoids are divided into two large groups
along geographic lines: Platyrrhini (New World
primates) and Catarrhini (Old World primates).
They all have flat faces, larger brains
(than Prosimians), fully forward facing eyes
and more manipulative hands.
Platyrrhines
There are two families within the New World
monkeys:
The callitrichids consist of marmosets and
tamarins, which are small-bodied primates that
live in Central and South American rain forests.
Several unique features include their dentition
(they have one fewer molar in each quadrant than
other Anthropoids) and the fact that they have
clawlike nails instead of flat nails.
In addition to these physiological characteristics,
callitrichids also live in polyandrous groupings
(i.e., single female with more than one male).
The second family, Cebidae, consists of six
subfamilies that encompass a wide range of
ecological and social diversity. This group also
includes the only noctural Anthropoid, the owl
monkey or night monkey; additionally, several
species of cebids also possess prehensile tails.
The cebids are all primarily arboreal, and exhibit
a number of different social systems.
Catarrhines (old world)
The catarrhine primates are generally larger than
platyrrhines; additionally, aspects of the physiology
(e.g., catarrhines have only two premolars in each
quadrant vs. three for platyrrhines) and ecology (e.g.,
catarrhines are found in many terrestrial habitats)
differ between these groups. Catarrhines can be
divided into two superfamilies, the Cercopithecoidea
(Old World monkeys) and the Hominoidea (apes).
The cercopithecoids have two general groups, which
can be divided along ecological and dietary lines: the
Colobine monkeys are distinguished by their
specialized stomachs, which have been modified for a
highly folivorous, or leaf-eating, diet. Additionally,
Colobines tend to live in single-male, multifemale social
groupings. Cercopithecines, the other group within the
Cercopithecoidea, are composed of a cohort of
monkeys that exhibit a wide range of dietary,
ecological, and social preferences.
There are many terrestrial species, and their
geographic distribution includes Africa as well as Asia
(and in one case, Gibraltar as well).
The apes represent a tailless group of large-bodied
primates. The classification Hominoidea includes both
lesser (e.g., gibbon, siamang) and great apes
(orangutan, gorilla, chimp, human). The apes are
generally allocated into one of three families:
1. Hylobatidae includes the lesser apes.
2. Pongidae includes the great apes, minus humans.
3. Hominidae includes humans and their fossil
relatives.