Primates
Primates: Characteristics
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In general, characters used to define
primates are not unique to the group,
and tend to be associated with
arboreality.
Primates: Characteristics
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Teeth are bunodont
and brachydont.
They exhibit
specialization of the
hands and digits:
– Nails vs. claws.
– Pads.
– Ridges.
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All primates have a
post-orbital bar with
some level of
binocularity.
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Enalrgement of
Cerebral cortex.
Reduced olfaction
and increased visual
importance
(stereoscopy –
color).
Diet.
Sociality.
Primate Evolution
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Formerly, primates were divided into
prosimians and anthropoids. However,
this results in some unnatural groups.
Today, we divide the primates into
Strepsirhines and Haplorhines.
Haplorhines include Tarsiers and
simians. Strepsirhines include lemurs
and lorises.
Primate Evolution
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Note the position of the Plesiadapids
and the Paromomyids.
Primate Evolution
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The floor of the auditory bullae in
primates are covered by the petrosal
bone.
Primate jaws have little lateral mobility
(compared to rodents).
Primates are plantigrade – some forms
have lost the hallux and/or pollex.
Primate Evolution
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Earliest fossils date to the Cretaceous
of Europe and North America.
Plesiadapis lacked a postorbital bar,
was relatively small and squirrel-like.
The tibia and fibula are separate,
allowing rotation of the hind-limb. Why
is this important?
Digits are long, and terminal digits had
claws, not nails.
Primate Evolution
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What can you infer from the skull
structure of Plesiadapis?
– Note: teeth, jaw, size of braincase.
Primate Evolution
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Adapids are derived from the
Plesiadapids, and show up in the
Eocene of Eurasia and North America.
They are possible ancestors to modern
lemurs. The forests of Europe and N.
America were tropical in the Eocene.
Smilodectes had a postorbital bar, long
tail, binocularity, no diastema, and an
offset first digit on each foot. They too
were small.
Primate Evolution
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Omomyids probably evolved from the
plesiadapids in the Oligocene and
Eocene of North America and Europe.
Tetonius and Necrolemur had large
eyes (nocturnality?), binocularity, a
short rostrum, underived teeth, large
canines.
Probably gave rise to the tarsiers.
Eocene Adapid: Notharctus and
Anaptomorphid: Tetonius.
Primate Evolution
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Modern new world families include the
Callithrichidae and Cebidae. Their
modern distribution is in south and
central America. Fossil record is poor.
Cercopithecidae of the old world have a
better fossil record, including the
Oligocene through Recent epochs.
Primate Evolution
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The jaw of Parapithecus has a condyle
which is high on the ascending ramus –
very similar to that of modern
cercopithecid primates. These are
ancestral to hylobatids and hominids.
Did primates evolve in trees or on the
ground? Consider the morphological
characteristics we have covered.
Miopithecus: hind limb dominance?
Strepsirhines
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7 families, primarily in Madagascar.
These are the “prosimians” – lemurs
and lorises.
Differ from Haplorhines by possession
of a rhinarium.
Possess a bicornate uterus.
Dental formula is 2/2, 1/1, 3/3, 3/3.
Strepsirhines
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Placenta is noninvasive epitheliochorial.
Young are relatively small compared to
female.
These traits are plesiomorphic, and
unite the strepsirhines, probably as a
monophyletic group.
Strepsirhine: Daubentoniidae
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Aye-ayes: Daubentonia
madagascariensis.
Monotypic.
Derived from same ancestral stock as
lemurs and lorises.
Solitary, nocturnal insectivores of
lowland forests in Madagascar. Note
long finger for tapping and extraction.
Virtually extinct – but one protected by
custom, now viewed as ‘evil.’
Strepsirhine: Daubentoniidae
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What do you make
of this skull of an
Aye-aye?
Hand and foot of an Aye-aye.
Strepsirhine: Loridae
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Lorises and pottos: 4 genera and 6
species. Range includes sub-saharan
Africa, India, Southeast Asia, Indonesia,
and the Philippines.
Small, flattened faces, nocturnal,
arboreal, dark thick wooly fur.
Pollex is 180º from remaining digits –
semi opposable.
Strepsirhines: Loridae
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Second digit is reduced
in most.
Second toe modified as
‘toilet claw’ in some.
Insectivorous and/or
frugivorous.
Live singly or paired,
have vocalizations w/
some facial expressions
– also scent mark.
Strepsirhines: Galagonidae
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Bushbabies of Africa. 4 genera and 11
species.
Arboreal – studied extensively because
of leaping ability. Have long hind-limbs
and a long tail.
Galagoides demidoff (60g) to Otolemur
crassicaudatus (1.2Kg).
Pentadactyl w/ second toe modified as
toilet claw. Insectivorous/omnivorous.
Strepsirhines: Galagonidae
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Live in groups of up to 9 animals.
Use urine-marking, facial expressions,
body posture, and vocalizations that
sound like a human baby crying (hence
the name).
Strepsirhine: Galagonidae
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Note the incisiform
canine.
Note rostrum on skull of Galago.
Strepsirhines: Lemuridae
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4 genera and 10 species.
Madagascar only, diurnal or
crepuscular, and arboreal, but may
spend time on ground.
Differ from other strepsirhines by small
eyes (dirunal), and rostrum.
Eat fruit, flowers, and vegetation.
Lower incisors and canines form
procumbent dental comb for auto and
allogrooming.
Strepsirhine: Lemuridae
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All species have ear tufts.
Eulemur macaco shows sexual
dichromatism.
All except Lemur catta (ring-tailed
lemur) use leaping and clinging for
locomotion. Lemur catta is quadrupedal
and climbs.
Social groups up to 20, scent and urine
marking. Sternal glands, cutaneous
arm glands. Vocal, posture, and facial
communication.
Strepsirhine: Megaladapidae
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Sportive lemurs – nocturnal and
arboreal. Eat leaves, bark, fruit, and
flowers.
Vertical clinging and leaping locomotion,
has prehensile thumb.
Solitary, some scent and urine marking.
Extensive vocal communication.
Strepsirhine: Cheirogaleidae
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Dwarf and Mouse lemurs: 4 genera and 7
species, all in Madagascar.
Large forward facing eyes, muzzles, arboreal
and nocturnal. Locomotion is squirrel-like,
but Microcebus is a leaper.
Insectivorous (Microcebus) or insects and
fruit.
Solitary or paired, posture, facial, vocal
communication, although less than in other
strepsirhines.
Strepsirhine: Indridae
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3 genera and 5 species, all in Madagascar.
Nocturnal and arboreal.
Includes Propithecus (sifakas – look like me)
and Indri, the largest Strepsirhine primate
(10Kg, short tail). Eat leaves, fruit, flowers,
and bark.
Vertical clinging and leaping. Hind limb
dominance.
Groups of 3-6, Vocal, scent, facial,
communication.
a) lemur, b) sifaka, Indridae, c) aye-aye, and
d) potto, Loridae.
Primate Evolution
Haplorhines
Note: haplorhines are found in Africa, Asia, and
Central & South America. Also, they have spatulate
incisors, a hemochorial placenta, and a postorbital
plate.
Tarsiidae
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A single genus w/ 5 species.
Found in Indonesia, Malay archipelago,
and the Philippines.
Fossil forms from N. America and
Europe.
Extreme ability to rotate head.
Crepuscular & nocturnal. Vertical
clingers and leapers.
Eat insects, lizards, and spiders.
Tarsiers
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Form pair bonds.
Territorial.
Produce a single precocial young.
Note Tarsier foot in center,
compared to lemur and gorilla.
Skulls of Galago and Tarsius.
Galago (top) and Tarsius.
Cebidae
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These are new world monkies.
11 genera and 58 species.
Most well known forms are Howler
monkeys, capuchins, spider monkeys,
uakaris, sakis, and woolly monkeys.
Primarily herbivorous/frugivorous, but
night monkeys eat insects and small
mammals.
Cebidae
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4 genera have prehensile tails, most
have prehensile hands, and the thumb
is only pseudo-opposable.
Aotus and Callicebus form
monogamous groups,while others form
polygamous groups w/ 5 to 100
individuals.
Callithrichidae
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This is the second group of new world
monkeys: 5 genera and 26 species of
marmosets and tamarins.
They are small, and consume insects
and fruit.
Quadrupedal, but can hop. They have
prehensile hands w/ non-opposable
thumbs.
Callithrichidae
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Live in extended family groups based
on monagamous pair with as many as
15 individuals.
Maintain territories up to 40 ha.
W/in group, only 1 female breeds
annualy, producing non-identical twins.
In Callimico, 2 female reproduce a
single young each twice each year.
All members of group carry young.
Olfactory, visual, marking-urinary
communication.
Compare skull of Aye-aye and
Marmoset (Saguinus geoffroyi).
Tarsier, Marmoset, spider, and Gorilla.
Cercopithecidae
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These are the old world monkeys. 18
genera and 81 species, in Africa, Asia,
and the Malay Archipelago.
Males have large canines, and
receptive females have perineal
swellings.
facial color, and facial expression are
important in communication, as is vocal.
Cercopithecidae
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Two major groups: cercopithecine
monkeys, and colobines.
Colobus monkeys lack cheek pouches,
have sacculated stomachs, and large
salicary glands. Most are folivores.
Primarily arboreal, but some are more
terrestrial, and all can move via
quadrupedal locomotion.
Cercopithecidae
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Social groups range from solitary
individuals to 100 or more. Most have
groups of 10 to 20, and are polygynous.
Hylobatidae
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These are one of 2 families of apes:
Hylobatidae and Hominidae.
Hylobatids are often lumped w/
Hominids, but Wilson and Reeder (the
bible of mammalian systematics) keep
them separate.
Hylobatids have 1 genus and 11
species.
Hylobatidae
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Found in S.E. Asia and the Malay
Archipelago.
There are 10 species of gibbons, and
the Siamang.
Facial features are ‘set off’ with fur.
Ture brachiators, with opposable
thumbs and fore-limb dominance.
Arboreal folivores / frugivores.
Hylobatidae
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Live in family groups as monogamous
pair w/ juveniles.
Parental care by males.
Territorial.
Both sexes ‘sing’.
Hominidae
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4 genera and 5 species:
– Gorilla gorilla
– Pan troglodytes & Pan paniscus
– Pongo pygmaeus Orangutan
– Homo sapiens
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All lack tails
K - selected life history.
Hominidae
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Orangutan males have large home
ranges which intersect max # of female
ranges.
Brachiaters
Folivores, as well as insects, birds, and
small mammals.
Found only in Borneo and Sumatra.
Hominidae
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Chimps live in central Africa.
Sexual dimorphism.
P. troglodytes will consume meat.
Live in groups (12 -100 for P. t., and 6 15 for bonobos).
Hominidae
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Gorillas
Sexually dimorphic, w/ males up to 180
Kg.
Tropical rain-forests of East and West
Africa.
Folivores and frugivores.
Hominidae
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2 populations of Gorillas.
West Africa:
– folivorous & frugivorous
– groups of c. 5
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East Africa:
– folivorous
– groups of 5-30 w/ 1 silverback.
Hominidae
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Communicate via facial expression,
chest thumping, and vocalizations.
Compare the skulls of a
cercopithechid (baboon) and a
gorilla.
Molars of a) cercopithecid, b) cebid, c)
cercopithecid baboon, and d) Hominid- orang.
Hominidae
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Humans
– lineage is 5 - 10 million years old.
– Erect bipedalism
– sexual dimorphism
– gracile
– polygyny to polyandry.
– Communication is complex.
What
can
you
say
about
this
skull
?