CHAPTER 4

Question 1

sprawling stance

Answer 1

an animals humerus and femur project horizontally, with elbows and knees strongly bend.

Question 2

Erect stance

Answer 2

an animals humerus and femur project vertically, such that the limbs point straight down from their girdles

Question 3

advantage and disadvantage to an erect stance

Answer 3

Advantage:
- positions the limb bones directly under the body, this allows to passively support the body weight

-Better for fast locomotion and allows all limbs to contribute to the length of a stride

disadvantage:
- requires muscle to do not my work then a sprawling stance would do.

Question 4

what do all tetrapods share a common ancestor with

Answer 4

a common ancestor with a sprawling stance.

Question 5

were dinosaur erect or sprawling

Answer 5

erect

Question 6

advantages and disadvantages for sprawling stance

Answer 6

advantages:
- less energy is spent to support body weight

Disadvantage: unable to move fast and

Question 7

Cursorial limbs

Answer 7

are limbs specially adapted for fast locomotion. tend to have very long lower legs bones

Question 8

digitigrade posture

Answer 8

stand on their own toes

Question 9

plantigrade posture

Answer 9

stand simultaneously on our toes and the flat part, and our heels

Question 10

graviportal limbs

Answer 10

• specially adapted for supporting extremes body weight.
• have bones that are robust and heavy. limbs tend to be short and bend as little as possible when walking
• tend to have large fleshy pads to provide solid support base and help absorb impacts

Question 11

obligate bipeds

Answer 11

animals that almost always walk and run on two legs.

Question 12

obligate quadrupeds

Answer 12

animals that almost always walk and run on four legs.

Question 13

facultative bipeds

Answer 13

walk on all four legs, but rise on two legs to run.

Question 14

what was the walking stance of the ancestor for all dinosaurs

Answer 14

obligate biped

Question 15

caudofemoralis

Answer 15

• a large muscle that pulls backwards on the hid leg,

- is anchored to the under surface of the ilium, to the caudal vertebrae, it attaches via tendon and femur

Question 16

trochanter

Answer 16

a prominence of bone,

Question 17

what does a larger caudofemoralis indicate ?

Answer 17

that the dinosaur was most likely a fast runner and was adapted for greater hindlimb power.

Question 18

where is the caudofemoralis located on most theropods

Answer 18

located high on the femur

Question 19

Ichnofossils

Answer 19

fossils that record traces of biological activity, like fossil footprints and tooth mark and burrows.

Question 20

how does a footprint fossilize ?

Answer 20

1) must be made in soft mud
2) mud must dry out and Harden
3) must be buried and then eventually re-exposed for the palaeontologist to find

Question 21

trackways

Answer 21

an entire series of footprints found.

Question 22

what were hadrosaurs and iguanodons?

Answer 22

facultative bipeds

Question 23

were dinosaurs cold or warm blooded

Answer 23

warm blooded

Question 24

which is ectotherm

Answer 24

cold-blooded

Question 25

which is endotherm

Answer 25

warm-blooded

Question 26

Ectotherms

Answer 26

animals that adjust their internal body temperatures through behaviours that depends on temperature differences within their environments

Question 27

Endotherms

Answer 27

animals that regulate their body temp through metabolic activity

Question 28

disadvantage of endotherms

Answer 28

In order to maintain a constant body temp, a lot of energy is spent to do this.

Question 29

are most organism ectotherms or endotherms

Answer 29

ectotherms

Question 30

advantages to endotherms

Answer 30

• can survive in the cold.
• always ready for actions, cold or warm, day or night.
• instead of spending time sunbathing like ectotherms, they spend that time eating and gaining energy.

Question 31

do endotherms or ectotherms benefit from feathers and shit

Answer 31

endotherms because it helps them hold o to body heat.

Question 32

Histology

Answer 32

a technique of slicing samples of bones into very thin sections

Question 33

osteons

Answer 33

bone cells

Question 34

which group grow their bones quicker then the other

Answer 34

endotherms from bones faster then ectotherms. they also have their osteons in a different arrangement.

Question 35

giganthermic

Answer 35

instead of being endotherms, large dinosaurs ectothermic, but with their low ratio of surface area to volume, it would have prevented them fro losing significant energy to the outside world. they could live endothermic-like lives without actually needing to produce body heat by burning energy.

Question 36

cube square law

Answer 36

the larger the animal is, then they have relatively less surface area to volume ratio.

Question 37

Dinosaurs that are obligate quadrupeds

Answer 37

• sauropods
• ankylosaurs
• stegosaurs

Question 38

what were prosauropods walking stance

Answer 38

probably bipedal, but whether they were obligate or facilitative is unknown.

Question 39

where does the caudofemoralis attach to

Answer 39

it attaches to the trochanter.

Question 40

how do we know dinosaur have caudofemoralis

Answer 40

Dinosaurs have a femurs with trochanters (prominence of bone)

Question 41

how can you determine whether a dinosaurs had a large cuadofemoralis

Answer 41

based on the size of the various anchor points.

Question 42

where is the caudofemoralis located on carnivores?

Answer 42

higher on the femur. this increase the speed.

Question 43

where is the caudofemoralis located on hadrosaurs

Answer 43

lower on the femur. this slowed down the speed but better endurance.

Question 44

who benefits from having higher endurance

Answer 44

herbivores recuasse hey are always on the move.

Question 45

what can trackways determine?

Answer 45

can determine how fast dinosaurs moved.

Question 46

how can trackways be used to determine a dinosaurs speed.

Answer 46

estimate dinosaur leg lengths from the proportions of their footprints. full speed cannot be determine because they had to run through mud.