PRIMATES

Question 1

What is the main diet of primates?

Answer 1

• Most are omnivores
• Some are specialised e.g. leaf eaters

Question 2

How are leaf eating primates adapted for their diet?

Answer 2

• Specialised stomach in order to digest cellulose
• Use of bacteria and enzymes within the stomach to aid digestion

Question 3

What are the main body characteristics of primates?

Answer 3

• Retention of clavicle: allows limb movement in all directions
• Elbow joint - rotation of the forearm
• 5 digits on fore and hind-limbs
• Reduced snout and reduced olfactory system
• Reduced number of teeth
• Nails
• Fleshy sensitive pads at the tip of the fingers

Question 4

Features of primate skull and brain

Answer 4

• Posterior skull (most of the skull is posterior to the orbits)
• Enlarged brain case
• Enlarged cerebral cortex compared to other mammals

Question 5

Primate eyes

Answer 5

• Forward facing eyes
• Binocular vision
• Depth perception
• Can detect fruits against a background
• Bigger orbits in primates than in other mammals
• Thought the good vision is associated with fruit eating

Question 6

What benefits comes with having opposable thumbs?

Answer 6

• Increases dexterity
• Allows manipulation of objects
• Moving around trees

Thought that primates evolved from an ancestor that had opposable thumbs for tree climbing

Question 7

What group are the basal primates in?

Groups of primates

Answer 7

Prosimians (before apes)

Question 8

Examples of Prosimians?

Groups of primates

Answer 8

Lemurs, bush babies, pottos, tarsiers etc

Question 9

Features of the Prosimians ?

Answer 9

• Small
• Nocturnal
• Small brains
• Relatively long snout (lemurs)
• Paraphyletic - dry nosed
• Basal primates - branched off early

Question 10

What group are monkeys and apes in?

Answer 10

Anthropoids

Question 11

Examples of Anthropoids
?

Answer 11

• New world monkeys
• Old world monkeys - baboons etc
• Lesser apes - gibbons
• Great apes - chimpanzees, gorillas etc

Question 12

Features of Anthrpoids?

Answer 12

• Mostly larger than prosimians
• Larger brain
• Relatively small olfactory lobes
• Mainly frugivorous or folivorous
• Mostly dinurnal
• Complex social structures
• Different types of locomotion

Question 13

What is the alternative classification of Prosimians and Anthropoids?

Answer 13

• Strepsirrhini (basal)
• Haplorrhini

Question 14

Features of Strepsirrhini?

Answer 14

• Small, long snout (rostrum), nocturnal
• 2 halves of lower jaw unfused. Frontal bones unfused
• Lack of orbital septum (hole behind orbit)
• Postorbital bar
• No plate seperating orbits from temportal fossa

Question 15

Example of strepsirrhini?

Answer 15

Lemur, Loris, pottos, Galagos

Question 16

Haplorrhini examples

Answer 16

• Tarsiers
• Old world monkeys
• New world monkeys
• Apes

Question 17

What is the main difference between the 2 ways of classifying primates?

Answer 17

• Prosimians - Anthropoids includes tarsiers along with lemurs etc
• Strepsirhini - Haplorrhini includes tarsiers with NWM, OWM and the Apes.

Question 18

Haplorrhini skull features

Answer 18

• Relatively short rostrum
• Plate that seperates orbits from temporal fossa

Question 19

New world monkeys: Features

Haplorrhini

Answer 19

• Platyrrhini (broad-nose)
• 3 premolars (more primitive state)
• Relatively good sense of smell
• Can have prehensile tail

Question 20

Life history traits of new world monkeys?

Haplorrhini

Answer 20

• Colonised South america from africa - 30mya
• Only arboreal forms - No terrestrial radiation e.g. like baboons

Question 21

Characteristics of Old world monkeys

Haplorrhini

Answer 21

• Catarrhini (narrow-nosed)
• Nostrils forward and down
• Smaller bone
• Never have a prehensile tail (tails often disappeared)
• 2 premolars
• Trichromatic colour vision - strongly associated with diet
• Poor sense of small - only 50% of olfactory genes are functional

Question 22

Life history traits of old world monkey examples

Haplorrhini

Answer 22

• Found in Asia and Africa
• OWM are more species rich and specialised
• Colobines - colobus monkeys - leaf eaters - stub thumbed
• Cercopithecines - vervet monkey - short tails, terrestrial - cheek pouches to carry food - longer thumbs but shorter fingers

Question 23

What are the two groups within old world monkeys?

Answer 23

• Colobines
• Cercopithecines

Question 24

Characteristics of Apes?

Haplorrhini

Answer 24

• Broader chest
• Scapula position is different - dorsal
• Greater curvature of ribs
• Caudal vertebrae reduced
• Front skull – Characterised by sinuses
• 5 cusps on molars
• Vertebral column altered for locomotion
• Bipedal pose - centre of gravity near vertebral column

Question 25

The social systems of primates: Female transfer

Answer 25

* **Group size**: small * **Number of males in group**: one or many * **Male behaviour**: Territorial (sometimes kinship groups) * **Examples**: Chimp, Gorilla, Baboons & Colobus.

Question 26

Primate Social Systems: Male Transfer

Answer 26

* Groups size: **Large** * Number if males in group: **One or several** * Male behaviour: **Male hierarchy** * Examples: **Most Ceropithecines (sub order of OWM).**

Question 27

Primate social systems: Monogamous

Answer 27

* Groups size: One family * Number if males in group: One * Male behaviour: Both sexes participate in defence and parental care * Examples: Gibbons and tamarins

Question 28

Primate social systems: Solitary

Answer 28

* Groups size: Single (or with offspring) * Number if males in group: None * Male behaviour: Range overlaps with range of >1 female * Examples: Bushbabies and Orangutans