Lecture 13

Question 1

What do different teeth have different types of?

Answer 1

. Enamel

. Surfaces to them which can aid the variety of dietary items

Question 2

Which teeth are for cropping and tearing?

Answer 2

Incisors and canines

Question 3

Which teeth are for crushing and shearing?

Answer 3

Premolars and molars

Question 4

What order is Sorex (shrew) in?

Answer 4

Lipotyphla

Question 5

What does it mean if teeth are deciduous?

Answer 5

Are replaced. Will decrease/ fall out (we the jaw gets bigger you have more space for more teeth

Question 6

Describe the teeth of shrew

Answer 6

. Dental formula of 44
. All teeth but molars are deciduous
. Incisors are highly modified- unique derived character state= autapomorphy (one of the defining characteristics of the species

Question 7

Describe the cheek tooth (molars) specialisation Bunodont common in omnivores. Give examples

Answer 7

On top they aren’t sharp
. Quite rounded
. Completely covered by enamel
. Quite flat
They are quite common of omnivores eating berries- crushing e.g. fruit bags (Megachiroptera), bears (Carnivora: Ursidae), pigs (Artiodactyla: Suidae), humans (primates: Hominoidea)

Question 8

Describe the cheek tooth (molars) specialisation Lophodont, common in herbivores. Give example

Answer 8

. Ridged grinding surfaces
. Dentine is exposed 
. Common in herbivores which gives them sharp edges to break down material 
. Cement, dentine, enamel all exposed 
E.g. Rhinoceros

Question 9

Describe the cheek tooth (molar) specialisation Hyperodont. What is a disadvantage of this specialisation?

Answer 9

. Open-rooted for continuous growth (has not got a into the jaw)
. This means they will remain sharp so they don’t run out of tooth
. Disadvantage if there is a gap or you eat the wrong things then could end up with over growth

Question 10

Describe the cheek tooth (molars) specialisation Polyphyodont and give an example

Answer 10

. Cycles of teeth
. Don’t erupt vertically
. (Evolution of arm race with plants as they put silica to prevent being eaten)
. Elephants: 6 replacements/ sets of teeth and once they are gone they will starve

Question 11

Describe the evolution of cheek teeth (molars) in horses and why this has happened

Answer 11

. Progressive development of hypsodont (deep-rooted, well embedded in the jaw) cheek teeth since the late Tertiary (20mya)
. Seen as an evolutionary arms race involving grasses depositing progressively more silica in cell walls (as an anti-herbivore defence) so the horses need better teeth for processing that material

Question 12

Describe the cheek tooth (molars) specialisation Selenodont. Give an example and how it works

Answer 12

. Crescent shaped molars
. Convergent with hypsodonty in functional anatomy
. E.g. deer- exposed dentine and enamel. Gap between the incisors and the cheek teeth, known as diastema, allows nipping and grabbing the grass at the front and chewing at the back with the material moved around by the animals tongue (ruminants)

Question 13

Give the Latin name for fallow deer

Answer 13

Capreolus capreolus

Question 14

What kind of cheek teeth do carnivores have? What are they associated with? Give examples

Answer 14

. Sectorial: slicing carnassials
. Associated with tight jaw articulation
E.g. cats and dogs (Carnivora: canidae and felidae)

Question 15

Describe sectorial cheek teeth

Answer 15

Modification of the last premolar and the first molar, very sharp and lobed allowing the animal to slice and the animal to close the jaw tight

Question 16

In Artiodactyla (e.g. Cervidae) how are the teeth different to other mammals? Example of species

Answer 16

Complete loss of upper incisors, replaced horny pad

E.g. fallow deer

Question 17

Give the 4 incisor specialisations. Give species examples

Answer 17

. Gnawing: open rooted, enamel only on anterior surface, so self-sharpening: rats, mice, squirrels, beavers (Rodentia)
. Enamel on both sides: rabbits and hares (Lagomorpha)
. Different jaw articulation positions for gnawing and grinding
. The front teeth overhang so, they have to move the jaw, depending on whether they are gnawing or grinding, because they couldn’t chew plant material while nipping off the same time

Question 18

Sweat does incisor specialisations dependent on?

Answer 18

The need for additional strength as to if they have enamel on both side

Question 19

Teeth are not necessarily just for feeding, what else are they for?

Answer 19

Reproduction- sexual selection

Question 20

What type of diet is acid digestion in the stomach effective for? Give examples

Answer 20

. Omnivores (mixed diet)
. Carnivorous
. E.g. Lipotyphla, Carnivora, Hominoidea

Question 21

What do herbivores require so they can digest cellulose?

Answer 21

Intestinal symbionts

Question 22

Which animals are foregut fermenters? Give examples

Answer 22

Ruminants (Artiodactyla) e.g. cows, sheep, goats, moose, common warthog

Question 23

Why are all species of foregut fermenters large?

Answer 23

Slow system prone to inhibition by tannins; so all species are large

Question 24

How do herbivores tackle digestion differently to carnivores?

Answer 24

. Spend a lot of time chewing
. Material will not pass into the acid stomach until it is well broken down, the starch and silica cell walls are all broken down

Question 25

How many chambers are there in foregut fermenters stomachs?

Answer 25

4

Question 26

Why are hindgut fermenters usually smaller or more leanly built than foregut fermenters? Give examples of hindgut fermenters

Answer 26

They have a faster system because it is more efficient and tend to be more resistant to tannins
E.g. zebra, rabbits, horses

Question 27

Smaller species have evolved coprophagy. What does this mean? Give an example

Answer 27

Means they eat faeces
E.g. rabbits,
Capybara- hydrochoerus hydrochaeris

Question 28

Why have some species evolved Coprophagy?

Answer 28

Faeces has nutrients still left over/ the material has not been fully processed

Question 29

Why is Coprophagy seen in smaller species/ species with a smaller gut?

Answer 29

The passage time is much smaller

Question 30

What modification do wombats have and why?

Answer 30

Have a modified gut so have square ooo to scent mark so it doesn’t roll away

Question 31

What do foregut fermenters allow more utilisation of?

Answer 31

Cellulose

Question 32

Define home range

Answer 32

Area you need to do about your daily business

Question 33

What does home range size correlate with?

Answer 33

The size of the animal