FC2: Form, Function & Sauropod Dinosaurs (W10b)

Question 1

Sauropod dinosaur attributes? (6)

Answer 1

• Largest terrestrial animals ever.
• Herbivores.
• Long necks.
• Earliest members from SA, Lesotho & Zimbabwe.
• World’s largest dinosaurs.
• Global distribution.

Question 2

How/Why did Sauropods have a global distribution?

Answer 2

Because they were distributed while the continents were still Pangea, i.e., before continents split.

Question 3

Why are Sauropods successful in distribution? (7)

Answer 3

• Appendicular skeleton.
• Axial skeleton.
• Skulls.
• Feeding & digestion.
• Growth rates.
• Circulatory system.
• Respiratory system.

Question 4

Sauropod appendicular skeleton attributes? (3)

Answer 4

• Limbs suggest slow, plodding movements.
• Not a cursorial.
• Foot = digitigrade.

Question 5

Why are Sauropods digitigrade?

Answer 5

Compare with elephant hind feet to figure out why.

Question 6

Elephant hind feet attributes? (3)

Answer 6

• Look plantigrade from outside.
• Foot bone posture shows digitigrade.
• Have a fatty cushion under their heels.

Question 7

After comparison between elephant hind feet, why are Sauropods digitigrade?

Answer 7

It may be that they had a fatty cushion under their heels.

Question 8

Sauropod front foot attributes? (2)

Answer 8

• Formed into a “colonnade”.
• No modern analogue.

Question 9

Colonnade?

Answer 9

= a tight cylinder of bones with no pad.

Question 10

Sauropod axial skeleton attributes? (3)

Answer 10

• Unconstrained vertebrae number.
• Opisthocoelus vertebrae.
• Use of beam mechanics to support neck.

Question 11

Sauropod skulls attributes? (6)

Answer 11

• Jaw has incisors only.
• Weak lower jaw.
• Homodont dentition without cusps.
• Short Lo.
• Long Li.
• No chewing (swallows food whole).

Question 12

Why are Sauropod’s head so small?

Answer 12

Because it wouldn’t make sense to have a big head as it would be difficult to support a huge head with a slim, long neck.

Question 13

Sauropod digestive system attributes? (6)

Answer 13

• Swallows food whole.
• 2 weeks digestion.
• Have big appetites.
• Hindgut fermenters.
• Use stomach as compost heap.
• Have gizzard & ceca.

Question 14

Why is it concluded that Sauropods have a gizzard & ceca?

Answer 14

It was acquired from their common ancestor through the phylogenetic bracket.

Question 15

Explain the experiment that scientists did to figure out Sauropod digestion?

Answer 15

Scientists used garbage cans full of ground up plant matter & bile salts to simulate Sauropod digestion.

Question 16

Pro of Sauropod long neck?

Answer 16

Don’t need to move body to feed which favours the use of the gut as a compost heap (feeding envelope).

Question 17

Sauropod growth rates attributes? (3)

Answer 17

• Inferred in a similar manner that tree growth rate is inferred.
• High growth rates in favourable conditions (i.e., more food, water, etc).
• Low growth rates in unfavourable conditions (i.e., drought, winter).

Question 18

How are growth rates of Sauropod inferred? (2)

Answer 18

• Cross-section of bone is observed under a microscope & histological slide with growth rings provide information on growth rate during seasons & age.

• Via Osteohistology.

Question 19

Sauropod circulatory system attributes? (2)

Answer 19

• Heart rate scales inversely with body mass.
• Heart size scales proportionally with body mass.

Question 20

Eg of Heart rate vs Body mass?

Answer 20

Shrew heart rate (~1000bpm)
&
Sauropod heart rate (~5bpm).

Question 21

Sauropod heart size?

Answer 21

100kg-300kg.

Question 22

Circulatory system problems of long-necked organisms/sauropods? (3)

Answer 22

• Pump blood against gravity when lifting head.

• Blood moves towards brain with speed (dangerous) when lowering head.

• Blood pooling in the legs.

Question 23

Solutions to sauropod circulatory system problems? (3)

Answer 23

• Rete mirabile to decrease blood pressure through narrowing blood vessels (for when head is lower).

• Jugular valves help control blood flow.

• Use of the colonnade & valves in the veins to solve blood pooling.

Question 24

Sauropod respiratory system problem?

Answer 24

Anatomical dead space.

Question 25

Anatomical dead space?

Answer 25

= volume of conducting airways without respiratory epithelium & not taking part in gas exchange.

Question 26

Solution to Sauropod respiratory system problem?

Answer 26

Use respiration that is now used by birds and all vertebrates, except mammals (pneumatization).

Question 27

Unidirectional flow?

Answer 27

= air only flows one way through the lung.

Question 28

Explain the way dead space is alleviated in birds?

Answer 28

Because bird lungs don’t change volume, they have a system of air sacs that change in volume & pump air through the lungs.

Question 29

Why do birds have pneumatic bones/skeleton?

Answer 29

For an efficient respiratory system through allowing space for air through the air sacs in their bones (pneumatization).

Question 30

Which animal is from the mystery question/largest dinosaur in South Africa?

Answer 30

Ledumahadi mafube.