THE ORDER PRIMATES
Lab 3, AN 102 Spring 2013
Dentition
Dental formula
(typical notation):
Ex) 2. 1. 2. 3
2. 1. 2. 3
Represents 1 “quadrant”
2 incisors, 1 canine, 2
premolars, 3 molars
Note – the top and bottom
dentition can be different
Teeth and Diet
Teeth have evolved
as mechanisms that
allow animals to
maximize energy
intake
Primate teeth
(mammal teeth) are
heterodont – a
varied pattern of
different-shaped
teeth
Teeth & Diet
Insectivore – Tarsier
Frugivore – Talapoin
Monkey (Guenon)
Folivore – Howler
Monkey
Teeth & Diet
Y-5 lower molars (apes)
vs
Bilophodont (OWM) molars
Primate Characteristics
Generalized mammals
Limbs & Locomotion
Tendency toward upright posture
Flexible, generalized limb
structure
Prehensile hands (and feet often)
Retention of 5 digits on the hands
and feet
Prehensile feet and hands in most
species
Flattened nails instead of claws
(hallux usually other digits)
Tactile pads with enhanced
sensory innervation
Diet & Teeth
Generalized dentition
Lack of dietary specialization
(omnivory)
Primate Characteristics cont.
Senses & Brain
Enhanced vision
Depth perception –
stereoscopic vision
Forward facing eyes –
binocular vision
Larger, more complex
visual cortex of the
brain.
Reduced olfaction –
smaller nose, loss of
rhinarium in
haplorrhines, smaller
olfactory area of brain
Expansion and
increased complexity of
brain.
Primate Characteristics cont.
Maturation, learning
and behavior
Longer gestation,
reduced number of
offspring (single
births), delayed
maturation, slow life
history
Greater dependence
on flexible, learned
behavior.
Tendency to live in
social groups
Tendency toward
diurnal patterns
Primate Taxonomy
Tooth Comb, No
Post-Orbital
Septum
S., C.
Ame,
2. 1. 3. 3
No Tooth Comb, PostOrbital Septum
Afr, Asia
2. 1. 2. 3
Y-5 Molars,
Loss of Tail
Bilophodont
Molars
Asia
Asia
Africa
Africa
Strepshirines
Strepshirines
Lemurs, Lorises,
Galagos
Characteristics
Tooth comb
Tooth comb
Rhinarium
Smaller relative brain
size
No post-orbital septum
Rhinarium,
wet nose
Strepsirrhines – The Post-Orbital
Connection
Strepsirrhines have Post-Orbital Bars, not PostOrbital Septa
This distinction can be slight – look carefully, consider
specimen D.
B
A
C
D
A. Ring-tailed
lemur lateral
view; B. Mouse
lemur cranial
view; C. Mouse
lemur frontal
view; D. Slender
loris fronto-lateral
view, note how
deep the POB is
in this specimen.
E. Pygmy marmoset –
note the complete postorbital septum
E
Haplorrhines
Strepsirrhines vs Haplorrhines
The most obvious differences distinguishing
strepsirrhines and haplorrhines are:
Haplorrhines lack tapetum lucidum (no red-eye)
Haplorrhines lack tooth comb
Haplorrhines have a post-orbital septum, in which at
least 2 bones form an enclosure for the eye
Tarsier trouble – tarsiers are the group that changed
primate suborder classification (from Prosimian/
Anthropoid to Strepsirrhine/Haplorrhine)
A
B
C
D
Post-orbital septum: A & B Pygmy marmoset, C. Red colobus, D. Tarsier (not to scale)
Platyrrhines
Platyrrhines
Platyrrhines are
haplorrhine primates
South and Central
America – all are
“monkeys”
All monkeys with
“prehensile tails” are
platyrrhines
Dental formula: 2.1.3.3
Except callithricids
Noses are flat with sidefacing nostrils
“Ear hole” is “ring-like” (as
opposed to “tube like”)
Catarrhines
Catarrhines
Catarrhines are also
haplorrhine primates, but
include the Old World
Monkeys and Apes
Asia and Africa
Dental formula 2. 1. 2. 3
Noses are downward
facing
Ear-hole is “tube-like” (as
opposed to “ring-like”)
Cercopithecoids
Cercopithecoids
The Cercopithecoids
are catarrhine
primates, and are
comprised of the Old
World Monkeys
Africa and Asia
Distinguished from
apes (hominoids) by:
Presence of tail
Bilophodont molars
Hominoids
Hominoids
Hominoids are catarrhine
primates, and are the Apes –
includes humans
Asia and Africa
Distinguishing features:
Lack of tail
Increased use of arms (high
arm:leg ratio)
Large bodies require large
amounts of food – many apes
have specialized masticatory
structures to process food
more efficiently
Bunodont molars (as opposed
to bilophodont molars)