Module 4.4
Hominid Studies
Glossary:
All words with ‘*’ can be found below, however, some definitions are found within the
text
Arboreal: Living in trees
Platyrrhini: New world primates
Catarrhini: Old world primates
Pseudo-genes: Remnants of genes that are no longer functional
The primate order:
, ● 6 subgroups = lemurs, lorises, tarsiers, New World primates/Platyrrhini, Old
World primates/Catarrhini and humans
● They all share several anatomical and functional characteristics showing their
common ancestry which began about 85mya
Evidence of primates having a common ancestor
● There is biological evidence of a common ancestor as all wild primates are
found in lands that previously were apart of the ‘mother’ continent
(Gondwanaland)
● The continental drift broke up Gondwanaland (180-200mya) which caused the
division between the primates
● Most present-day primates are arboreal* suggesting that they had an arboreal
ancestor
● These ancestors then diversified in arboreal habitats, of which many have
remained totally arboreal while others become partially terrestrial
Characteristics that are adaptations to arboreal life
● They kept their clavicle/collarbone which forms an important part of the
shoulder joint. This bone helps to stabilize the shoulder which supports the
weight of the primate when it hangs from its arms
● They have long, slender limbs that rotate freely at the shoulders and hips which
helps them move around trees
● They have mobile opposable thumbs in only the catarrhines* and a few lemurs
and lorries that have dextrous hands. Only some new world primates have a
prehensile tail
Other characteristics that all primates share:
● Enlarged and complex brain relative to body size
● A flattened face and reduced snout with a reduces the sense of smell (could
be because primates rely more on sight than smell
● Eyes that face forward so that the eyes’ visual fields overlap to give
stereoscopic vision
● Digits with flat nails
● Molar and premolar teeth with cusps that are low and rounded
● Complex social behaviour that usually only have one offspring at a time and
extended care for the young
Genetic evidence of a common ancestor for primates is slowly emerging,
Primates:
Hominid Studies
Glossary:
All words with ‘*’ can be found below, however, some definitions are found within the
text
Arboreal: Living in trees
Platyrrhini: New world primates
Catarrhini: Old world primates
Pseudo-genes: Remnants of genes that are no longer functional
The primate order:
, ● 6 subgroups = lemurs, lorises, tarsiers, New World primates/Platyrrhini, Old
World primates/Catarrhini and humans
● They all share several anatomical and functional characteristics showing their
common ancestry which began about 85mya
Evidence of primates having a common ancestor
● There is biological evidence of a common ancestor as all wild primates are
found in lands that previously were apart of the ‘mother’ continent
(Gondwanaland)
● The continental drift broke up Gondwanaland (180-200mya) which caused the
division between the primates
● Most present-day primates are arboreal* suggesting that they had an arboreal
ancestor
● These ancestors then diversified in arboreal habitats, of which many have
remained totally arboreal while others become partially terrestrial
Characteristics that are adaptations to arboreal life
● They kept their clavicle/collarbone which forms an important part of the
shoulder joint. This bone helps to stabilize the shoulder which supports the
weight of the primate when it hangs from its arms
● They have long, slender limbs that rotate freely at the shoulders and hips which
helps them move around trees
● They have mobile opposable thumbs in only the catarrhines* and a few lemurs
and lorries that have dextrous hands. Only some new world primates have a
prehensile tail
Other characteristics that all primates share:
● Enlarged and complex brain relative to body size
● A flattened face and reduced snout with a reduces the sense of smell (could
be because primates rely more on sight than smell
● Eyes that face forward so that the eyes’ visual fields overlap to give
stereoscopic vision
● Digits with flat nails
● Molar and premolar teeth with cusps that are low and rounded
● Complex social behaviour that usually only have one offspring at a time and
extended care for the young
Genetic evidence of a common ancestor for primates is slowly emerging,
Primates:
