Primates

Question 1

Where are primates found?

Answer 1

Every continent except Antarctica - due to spread of humans

Most primates confined to the tropics

Question 2

What are some general characteristics of the primates?

Answer 2

Mostly arboreal

Mostly omnivores with some being specialist leaf eaters

Have retention of the clavicle

Flexible shoulder joint - allows for limb movement in all directions

Flexible elbow joint - allows for rotation of the forearm

5 digits on fore and hindlimbs

Usually 1 young during pregnany

Posterior skull

Reduced snout

Reduction in number of teeth

Have nails

Have fleshy sensitive pads at tip of fingers

Enlarged brain with reduced nasal region

Forward facing eyes - binocular vision

Opposable thumbs with some exceptions

Question 4

What are the prosimians?

Answer 4

Basal primates that branched off early

Includes lemurs, bush babies and tarsiers

They all small, nocturnal and small brained

Question 5

What are the anthropoids?

Answer 5

Includes everything except prosimians - new world monkeys (4 groups), old world monkeys (2 groups), lesser apes and great apes

Mostly larger than Prosimians

Larger brain an relatively small olfactory lobes

Mainly frugivorous or folivorous

Variety of locomotion

Question 6

What is the new alternative classification of the primates?

Answer 6

Can split them into two major groups - the Strepsirrhini and the Haplorhini

Question 7

Give some features of the Strepsirrhini

Answer 7

Usually small

Long snouted

Nocturnal

Frontal bones unfused and lower jaw halves unfused

No orbital septum

Generalist diet

Distributed across Africa and Asia and Madagascar for the lemurs

Question 8

Compare the skulls of the Haplorrhini and the Strepsirrhini

Answer 8

Haplorrhini:

• relatively short rostrum
• plate separating orbits from temporal fossa

Strepsirrhini:

• relatively long rostrum
• postorbital bar
• no plate

Question 9

Give some features of the new world Haplorrhini monkeys

Answer 9

Platyrrhini = broad nosed:

• 3 premolars which is more primitive state
• Relatively good sense of smell
• Colonised South America from Africa around 30 MYA
• No terrestrial radiation
• has 5 groups
• e.g. howler and spider monkeys

Question 10

Give some features of old work Haplorrhini monkeys

Answer 10

Catarrhini = narrow nosed:

• more specialised and species-rich
• 2 premolars
• trichromatic colour vision
• poor sense of smell
• has 2 groups

Question 11

Give some features of Haplorrhini Apes (Hominoidea)

Answer 11

Broad thorax and dorsal position of scapula - to assist balance in a bipedal pose by placing centre of gravity near vertebral column

Caudal vertebrae reduced

Front skull has sinuses

5 cusps on molars