Week 3 - eating

Question 1

What’s the main way to determine a dino’s diet?

Answer 1

comparative anatomy

Question 2

What are some general adaptions of herbivores?

Answer 2

• thin, rigid or leaf shaped teeth –> shearing
• broad flat teeth –> grinding
• long legs and necks –> browse in trees

Question 3

What are some general adaptations of carnivores?

Answer 3

• sharp pointed teeth –> piercing
• shape hooked claws –> hold onto struggling prey
• teeth w serrated edges –> slice through flesh
• sharp teeth + strong round teeth + strong jaws –> puncture and rip flesh and crack bones

Question 4

What is durophagy?

Answer 4

consumption of bones

Question 5

what are frugivores and some adaptations?

Answer 5

eat primarily fruit
- beak = sharp and hooked –> rip and tear apart peals and husks of large tropical fruits

Question 6

what are piscivores and some adaptations?

Answer 6

eat primarily fish
- tall, sharp, conical teeth that lack serrations –> spearing and holding onto fish
- long jaws –> snap shut quickly
- procumbent dentition = teeth at the front pointed forward at and angle –> allows front tips of the jaw to be used to impale fish

Question 7

what are insectivores and some adaptations?

Answer 7

eat primarily insects
- sharp piercing teeth –> puncture the chitinous exoskeletons of insects
- weak jaws and reduced teeth (may have no teeth) –> swallow soft-bodied insects whole
- large spade-shaped claws + powerful short limbs –> digging

Question 8

What are some general adaptations of omnivores?

Answer 8

• unspecialized beaks and teeth or variety of teeth with diff shapes (canines = carnivorous teeth; molars = herbivorous teeth)

Question 9

What modern animals replace their teeth?

Answer 9

sharks and alligators

Question 10

Describe teeth replacement in dinos

Answer 10

1. when a old tooth is ready to be replaced, the root is reabsorbed
2. new teeth grow in and push upwards on the old teeth
3. after reabsorption, the crown is shed

Question 11

What is resorption and why is it important?

Answer 11

resorption = chemical process by which a dino breaks down its old teeth and bones

allows minerals and nutrients to be reused

Question 12

Why do herbivores have to replace their teeth more often?

Answer 12

teeth wore down faster due to grinding

Question 13

when is a crown usually shed?

Answer 13

during feeding

Question 14

how can we tell that a tooth was shed?

Answer 14

worn and lacks roots

Question 15

why is digesting plant material difficult? how do animals digest it?

Answer 15

cellulose is tough to digest

animals require bacteria to help digest cellulose, and chewing food helps

Question 16

what are dental batteries? what dinos have them? did it evolve indep or dep?

Answer 16

arrangements of densely packed teeth that collectively form a single, large chewing surface, found in hadrosaurs and ceratopsians (convergent evolution)

Question 17

How would have sauropods used their guts?

Answer 17

as fermentation tanks - did not chew food, so more time the food stayed in the gut, the better

Question 18

how did hadrosaurs use their dental batteries?

Answer 18

• chewing surface were angled down
• moved their jaws back and fourth and side to side

Question 19

How did ceratopsians use their dental batteries?

Answer 19

teeth in jaw would have slid together like scissors

Question 20

Why were dental batteries inset in the jaw (positioned close to the tongue)?

Answer 20

helped make room for large cheeks –> holding food

Question 21

what structure covers the outside of teeth, and which is found inside teeth?

Answer 21

enamel = covers outside
dentine = inside the tooth

Question 22

What kind of teeth did sauropods and ankylosaurs have? What was the consequence of this?

Answer 22

had simple teeth –> nip of vegetation, but only break down their food a little –> had extensive guts –> big rib cages to house the immensive GIT –> takes longer to get their energy + increase the volume of food that can be held in the GIT

Question 23

name two herbivourous theropods, and describe how they chewed their food

Answer 23

oviraptosaurus and ornithomimids –> lacked teeth but have gastroliths in their rib cages

Question 24

Describe how gastroliths work

Answer 24

gastroliths = small masses of little stones in gastric mills –> filled by swallowing pebbles –> help toothless animals chew their food via muscular contractions that grind the rocks together and against plants

Question 25

describe dromeosaurs and give an example of one

Answer 25

theropods with thin tails supported by special rod-like projections of their caudual vertebrae + chevrons, e.g. velociraptor

Question 26

describe the carnivorous adaptations of dromeosaurs and troodontids

Answer 26

1. serrated teeth
2. large sickle-shaped claw on each hind foot
   - resemble retractable claws and could be raised off the ground
   - keeping it raised –> keep the claw sharp
   - slash and puncture prey, help some climb trees

Question 27

Why are spinosaurs thought to be piscivores?

Answer 27

teeth are conical, have sharp tips and have few to no serrations

Question 28

Describe alvarezsaurs and give an example of one

Answer 28

• theropod with short front limbs and compact hands
• insectivores –> reduced teeth + short but strong front limbs
• shivuuia –> one large spade-shaped claw on each hand

Question 29

Describe the carnivoruous adaptations of tyrannosaurs

Answer 29

• teeth with serrated edges
• teeth have blunt tips –> attachment for jaw muscles –> increase bite force –> capable of durophagy

Question 30

What are some non-morphological indicators of diet?

Answer 30

1. cololites (fossil gut contents)
2. gastroliths
3. bite marks on bones
4. corpolites (poopies)