Moving Around

Question 1

Name for modern animals that have a sprawling stance.

Answer 1

lizard, turtle, crocodile, salamander`

Question 2

Name 2 (types of) animals that have an erect stance.

Answer 2

mammals, birds

Question 3

Describe the sprawling stance.

Answer 3

humerus and femur project horizontally; elbows and knees strongly bent

Question 4

Describe an erect stance.

Answer 4

humerus and femur project vertically (i.e. all limbs point straight down from their girdles)

Question 5

Is it more advantageous to have an erect stance or a sprawled stance? Why? (I.e. what are the advantages?)

Answer 5

more advantageous: erect stance

• having the limb bones directly under the body allows the limb bones to passively support the body’s weight (without muscle strain)
• having straight limbs contributes to stride length, which increases speed (b/c stride is longer)

Question 6

Why does it make sense for a lizard to have a sprawling stance?

Answer 6

relatively inactive; only rise to walk and run infrequently

Question 7

What stance did the ancestor of all modern tetrapods assume?

Answer 7

sprawling stance

Question 8

TRUE or FALSE: Birds and mammals evolved their erect stances independently of each other.

Answer 8

TRUE

Question 9

What stance did dinosaurs assume?

Answer 9

erect stance

Question 10

What are cursorial limbs specifically adapted for? Describe their strcture.

Answer 10

fast locomotion; long lower leg bones (below elbows and knees)

Question 11

What posture describes cursorial animals that stand on their toes?

Answer 11

digitigrade posture

Question 12

What posture describes cursorial animals that stand on their toenails/hoofs?

Answer 12

unguligrade posture

Question 13

Name 2 modern animals with cursorial limbs and digitigrade posture.

Answer 13

Cheetahs and ostriches

Question 14

Name 2 modern animals with cursorial limbs and unguligrade posture.

Answer 14

horses and antelopes

Question 15

TRUE or FALSE: humans are cursorial.

Answer 15

FALSE

Question 16

What posture do humans assume? Describe this posture.

Answer 16

plantigrade posture - standing simultaneously on our toes, flat of our feet, and our heels

Question 17

Which dinosaurs show cursorial adaptions? What are the indications?

Answer 17

ornithomimid theropods; digitigrade stance and long metatarsals

Question 18

What are graviportal limbs specially adapted for? Describe the bones and feet of these limbs. Are these limbs short or long? Do the joints bend a lot or very little?

Answer 18

adapted for: supporting extreme body weight
bones: robust and heavy
feet: large and padded
limbs: short
joints: bend very little

Question 19

What is an example of a modern animal with graviportal limbs?

Answer 19

elephant

Question 20

What is the term for an animal that walks and runs on 2 legs?

Answer 20

obligate bipeds

Question 21

What is the term for an animal that walks and runs on 4 legs?

Answer 21

obligate quadrupeds

Question 22

What is the term for an animal that walks on 4 legs but rises on 2 legs to run? What are some modern animal examples?

Answer 22

facultative bipeds; basilisk lizard, primates, kangaroos

Question 23

TRUE or FALSE: The ancestor of all dinosaurs was a facultative biped.

Answer 23

FALSE: The ancestor of all dinosaurs was an OBLIGATE BIPED.

Question 24

Which dinosaurs were obligate quadrupeds? Select all that apply

a) prosauropods
b) small ornithopods
c) sauropods
d) stegosaurs
e) pachycephalosaurs
f) hadrosaurs
g) iguanodonts
h) ankylosaurs
i) theropods
j) small ceratopsians
k) large ceratopsians

Answer 24

c) sauropods
d) stegosaurs
h) ankylosaurs
k) large ceratopsians

Question 25

Which dinosaurs were obligate OR facultative bipeds? Select all that apply a) prosauropods b) small ornithopods c) sauropods d) stegosaurs e) pachycephalosaurs f) hadrosaurs g) iguanodonts h) ankylosaurs i) theropods j) small ceratopsians k) large ceratopsians

Answer 25

a) prosauropods

Question 26

Which dinosaurs were obligate AND facultative bipeds? Select all that apply a) prosauropods b) small ornithopods c) sauropods d) stegosaurs e) pachycephalosaurs f) hadrosaurs g) iguanodonts h) ankylosaurs i) theropods j) small ceratopsians k) large ceratopsians

Answer 26

small ceratopsians

Question 27

Which dinosaurs were obligate bipeds? Select all that apply a) prosauropods b) small ornithopods c) sauropods d) stegosaurs e) pachycephalosaurs f) hadrosaurs g) iguanodonts h) ankylosaurs i) theropods j) small ceratopsians k) large ceratopsians

Answer 27

b) small ornithopods e) pachycephalosaurs i) theropods

Question 28

Which dinosaurs had strong hind legs that were significantly longer than their front limbs, but despite this indication of a bipedal stance, did not actually assume a bipedal stance? Select all that apply a) prosauropods b) small ornithopods c) sauropods d) stegosaurs e) pachycephalosaurs f) hadrosaurs g) iguanodonts h) ankylosaurs i) theropods j) small ceratopsians k) large ceratopsians

Answer 28

f) hadrosaurs g) iguanodonts (i.e. large ornithopods)

Question 29

What is the caudofemoralis? What is its function?

Answer 29

what: large muscle that pulls backward on the hind leg --> ANCHOR POINT function: power animals when they walk and run (e.g. crocodiles and birds)

Question 30

Describe where in the body the caudofemoralis is anchored?

Answer 30

anchored to: - the under surface of the ILIUM - CAUDAL VERTEBRAE - CHEVRONS note: attached by a tendon to the FEMUR

Question 31

What is the trochanter?

Answer 31

what: prominence of bone where caudofemoralis muscle-ligament attaches (MUSCLE ATTACHEMENT)

Question 32

What can we infer about a dinosaur that has large anchor points, like the caudofemoralis?

Answer 32

- this dinosaur is adapted for greater hindlimb power - probably a strong runner

Question 33

What can we infer about a dinosaur whose trochanter is located high on the femur?

Answer 33

- high trochanter = high muscle attachment; allows caudofemoralis to repeatedly retract quickly - probably carnivorous b/c legs can swing fast when hunting prey

Question 34

What can we infer about a dinosaur whose trochanter is located low on the femur?

Answer 34

- low trochanter = low muscle attachment; does NOT allow caudofemoralis to repeatedly retract quickly - probably herbivorous b/c legs don't need to move fast (as they do not hunt prey) - legs have much greater endurance b/c each retraction of the leg pulls with greater endurance

Question 35

Why is it advantageous for herbivorous dinosaurs to have a low trochanter?

Answer 35

low trochanter --> greater leverage with each leg retraction --> greater endurance for moving and grazing from one patch of vegetation to the next

Question 36

what is the name of fossils that records biological activity

Answer 36

ichnofossils

Question 37

what are some examples of ichnofossils

Answer 37

burrows, fossil footprints and tooth marks

Question 38

true or false - tooth marks are the best evidence of how a dinosaur moved

Answer 38

false - it is fossil footprints

Question 39

what are the steps for how a footprint can be fossilized

Answer 39

1. footprint must be made in soft mud 2. mud has to dry and harden 3. the footprint must be buried to protect it

Question 40

true or false - dinosaur footprints are common fossils

Answer 40

true

Question 41

what are trackways

Answer 41

it is an entire series of dinosaur footprints

Question 42

what do trackways tell us

Answer 42

posture, stride length and walking speeds

Question 43

true or false - bipedal dinosaurs hold their body in a vertical position

Answer 43

false - horizontal

Question 44

briefly explain the trackways left behind by hadrosaurs and iguanodonts

Answer 44

they leave deep imprints by their hindfeet and shallow tracks made by front feet

Question 45

true or false - longer strides enhance speed

Answer 45

true

Question 46

how can leg lengths of dinosaurs be estimated

Answer 46

from the proportions of their footprints

Question 47

true or false - trackways tell us about the dinosaur's walking and running speed

Answer 47

false - only walking speed

Question 48

_____ are animals that adjust their internal body temperature through behaviors that depend on temperature differences

Answer 48

ectotherms

Question 49

_____ are also known as warm blooded animals

Answer 49

endotherms

Question 50

how do endotherms warm themselves up and cool themselves down

Answer 50

they burn energy to generate internal heat they sweat/pant to cool down

Question 51

what is a disadvantage of being an endotherm

Answer 51

they must expand large amounts of energy , therefore having to consume a lot more food than ectotherms

Question 52

what are the four advantages of being an endotherm

Answer 52

1. can survive in cold climates 2. they can function the same as they could in the middle of the day; not sluggish like ectotherms 3. they can be out all day and night; sunny or cold 4 maintains high activity levels

Question 53

why do people believe that dinosaurs are mostly endotherms

Answer 53

they have hair like feathers that help them hold in body heat which they gain from burning energy

Question 54

briefly explain histology

Answer 54

a technique used to slice samples of bones into thin sections so that the internal structure of bone can be magnified

Question 55

bone cells are called a) osteoclasts b) osteons c) stem cells

Answer 55

b) osteons

Question 56

do endotherms or ectotherms grow their bones more quickly

Answer 56

endotherms

Question 57

true or false - larger dinosaurs are endothermic

Answer 57

false - they are gigantothermic

Question 58

explain the cubic square law

Answer 58

when the shape increases in size, its surface area increases more slowly than the volume

Question 59

using the cubic sqaure law , is this a false statement -> smaller animals have a large surface area compared to large animals

Answer 59

it is true