FEEDING

Question 1

Why is feeding so important?

Answer 1

• the transition from ectothermy to endothermy has meant that energy requirements are much higher

Question 2

Feeding begins in the (a) and mammals chew to create a food (b) which is swallowed.

Answer 2

a) mouth

b) bolus

Question 3

Edentate means what? give examples of species that come under this?

This was likely to be an example of ___ evolution.

Answer 3

Without teeth

• includes xenartha (armadillos)
  pholidota (pangolin)
• convergent

Question 4

What were the original triassic mammals like?

Answer 4

small and insectivores

Question 5

Where is the zygomatic arch? What is it composed of?

Answer 5

junction of squamosal and fugal muscles

Question 6

Where is angular process? Attachment for what muscle?

Answer 6

lower jaw, bottom right

• masseter

Question 7

Where is the coronoid process? Interlocks with?

Answer 7

Top right of lower jaw

- locks into the zygomatic arch

Question 8

Describe the two fossae

Answer 8

Temporal fossa on upper half of skull, attachment point

Massteric fossa, attachment point

Question 9

The temporalis muscle originates at the (a) fossa and inserts into the (b) process. What is its function?

Answer 9

a) temporal
b) coronoid
- to pull the mandible upward and backward

Question 10

The masseter muscle originates at the __ (a) ___ and inserts at both the (b) fossa and the (c) process. What is its function?

Answer 10

a) zygomatic arch
b) masseteric
c) angular
- to pull the mandible sideways and forward

Question 11

Pterygoideus muscle originates at the (a) plates and inserts into what? (b)

c) Also what function does it have? Same as?

Answer 11

a) pterygoid
b) medial angular process
c) - mandible upwards and forwards

Question 12

Why is the digastric muscle so weak?

Answer 12

because it functions to pull the jaw downwards but gravity does most of that work

Question 13

Function of teeth

a) incisors
b) canines
c) premolars
d) molars

Answer 13

a) nipping and biting
b) crushing and grasping
c) slicing and shearing
d) grind, crush, chew

Question 14

Why are occlusal surfaces important?

Answer 14

interlocking and interdigitation of teeth to maximise efficiency

Question 15

Distinguish between non-mammalian and mammalian teeth repair/ replacement? Why is this important?

Answer 15

• non-mammals can simply replace teeth by creating them between digits/ teeth
• mammal species will erupt new teeth beneath the original ones in order to maintain occlusion

Question 16

What is anisognathy?

Answer 16

the lower jaw is narrower and chewing is done on one size to improve occlusion

Question 17

What qualities of a carnivore skull allow a larger temporalis muscle than masseter?

What does this allow carnivores to do?

Answer 17

• wide zygomatic arch
• large temporal fossa
• large coronoid process
• small angular process
• large occpital region

-put greater emphasis on closing and biting DOWNWARDS

Question 18

Carnivores have a jaw joint that is (a) with the teeth line to allow the teeth to function like (b). Condyle of mandible allows the jaw to function like a (c).

Answer 18

a) level
b) scissors
c) hinge

Question 19

In herbivores the jaw joint is (a) from the tooth row, and is set much (b). This allows what?

Answer 19

a) offset
b) higher
c) teeth to come into contact simultaneously in order to allow grinding

Question 20

What qualities of a herbivore skull allow a large masseter muscle?

Answer 20

• narrow zygomatic arch
• large angular process
• small coronoid process
• small occipital region
• small temporal fossa

Question 21

What is a diastema?

Answer 21

where canines have been lost allowing cropping at front and grinding at rear

Question 22

The monotremata are an infraclass of the _(a)_theria.

Answer 22

proto

Question 23

a) What is a cloaca?

b) what kind of posture to the monotremata have?

Answer 23

a) one orifice where the eggs, urine and faeces all exit through
b) sprawling

Question 24

What do monotremata have instead of teeth as adults?

What does this mean for their skull?

Answer 24

• horny barbs or plates

- limited area for muscle attachment and weak jaw muscles

Question 25

How are leathery beaks used to detect prey?

Answer 25

electromagnetic signals

Question 26

The marsupials belong to the subclass __ and are also known as the __

Answer 26

theria

metatheria

Question 27

What is interesting about the Marsupial post canines?What function do they have?

Answer 27

they are all the same size

• shearing function

Question 28

Key differences in dental formula between metatheria and eutheria (ancestral forms)

Answer 28

• reduction in number of incisors
• more premolars
• 1 less molar

Question 29

When did Marsupials thrive?

Answer 29

tertiary

Question 30

Australidelphia is a good example of an ancestral (a) and its angular process is (b) and points (c)

Answer 30

marsupial

b) inflicted
c) inwards

Question 31

The infraclass Eutipolyphyla feed on (a) using mainly incisors which are specialised to pierce (b).

Answer 31

a) invertebrates

b) chitin

Question 32

How are the class Xenartha (anteaters) adapted for eating ants?

Answer 32

• huge reduction or loss of teeth
• little muscle attachment
• big salivary glands
• ripping forelimbs

Question 33

How are fruit eaters such as (a) adapted for eating?

Answer 33

have sharp anterior teeth for piercing fruit
- rounded palate

• CHIROPTERA (bats)

Question 34

Cetaceans are adapted in what sense?

Answer 34

baleen or increased teeth number for fish traps

Question 35

What characteristics change in the transition from carnivore to omnivore?

Answer 35

• reduced sagital crest

- elongated post canine teeth

Question 36

How have herbivores overcome teeth decay?

Answer 36

have very high crowned teeth

Question 37

What is a carnivore gut like?

Answer 37

• short caecum
• short intestine
• short colon

Question 38

Distinguish between ruminants and non-ruminants in herbivores

Answer 38

RUMINANTS - are foregut fermenters, 4 chambered stomach

NON-RUMINANTS - simple stomach but large ceacum