Vertebrates 11.2 - Running

Question 1

Step/Pace

Answer 1

Distance between right foot and left foot.

Question 2

Stride

Answer 2

Distance between position of one foot to that same foot again. (ie left foot to left foot)

Question 3

Phases of step cycle

Answer 3

Propulsive phase (power) and swing phase (speed). Both affect stride length

Question 4

Step cycle in amphibians and reptiles

Answer 4

Sinusoidal movements of trunk and tail. Need relatively thick body wall muscles and muscular limbs to support themselves off the ground.

Question 5

Animals that have lost step cycle

Answer 5

Snakes. Still move in sinusoidal pattern.

Question 6

Step cycle in salamander vs alligator

Answer 6

Gator has much less body motion and more of a step motion, therefore more limb muscles.

Question 7

Step cycle in mammals

Answer 7

Limbs are under the body, therefore vertical plane of movement.

Question 8

<p>

| Cursorial species</p>

Answer 8

<p>
Are able to run very fast (deer, pronghorn). Usually digitigrade or unguligrade. More joints and more places for muscles.</p>

Question 9

Pronghorn

Answer 9

Fastest land animal in NA, >90kph over long distances. Probably had a fast predator anciently, but no longer.

Question 10

Gaits

Answer 10

Combination of feet on or off the ground.

Question 11

Walk vs run

Answer 11

Walk always has limb on ground, running has a suspension phase

Question 12

Way of running

Answer 12

Trot = symmetrical (two legs in same step cycle) and gallop = asymmetrical. Gallop generally faster, longer suspension phase.

Question 13

Formula for speed

Answer 13

V = FxL. F = stride frequency, L = stride length.

Question 14

Cheetah adaptation for speed

Answer 14

Flexes the back a lot which adds to the stride length by bringing the hind limbs forward more. (stronger propulsive phase). Other animals do this to a smaller extent.

Question 15

Limb length - arrangements

Answer 15

Plantigrade (wrist/ankle on ground), digitigrade (metacarpals/metatarsals off ground), unguligrade (just end of phalanges on ground). More joints results in more speed.

Question 16

Adaptations for jumping (saltatory motion) in anurans

Answer 16

Modified skeleton. Long hindlimb, forelimbs fairly thick (fused radioulna), no tail, short strong trunk, pelvic girdle (Sacroiliac joint is flexible)

Question 17

Steps in jumping in anurans

Answer 17

Steps: 1. Push off with forelimbs. 2. Hindlimbs relaxed as possible then contract. 3. Rotate legs horizontally to decrease drag. 4. Sacroiliac joint bends to bend head down. 5. Land on forelimb.

Question 18

Adaptations for jumping kangaroos

Answer 18

Forelimb not used, not as much contraction of hindlimb, tail balances animal. Long achilles tendons with more elastic tissue recapture a lot of energy (O2 consumption doesn’t increase).

Question 19

Reading: Baird’s law of Ichnology

Answer 19

The study of footprints, trackways burrows, etc. Tell us the anatomy of animal, but also posture (quad/bipedal, balance) and movement and speed

Question 20

Reading: Tracks in Greenland

Answer 20

Found them in particularly muddy substrate - see more of how the foot interacted with the substrate

Question 21

Reading: What dinosaur made the Greenland tracks?

Answer 21

A small therapod, Compsognathus, about turkey sized

Question 22

Reading: How can you tell a therapod footprint from a bird’s?

Answer 22

The hallux in therapods are higher on the ankle, usually didn’t hit the ground.

Question 23

Reading: What experiment did the researchers do to strengthen their idea of therapod locomotion?

Answer 23

They ran turkeys and guineafowl on hard and sloppy substrate to compare them to the dino tracks. Found it was similar. They can see the angle of entry and exit of the foot.

Question 24

Reading: What was the conclusion of the dino study?

Answer 24

Birds and therapods walk essentially the same way, only birds’ hallux is lower and makes more of a mark in the ground

Question 25

Video: What was the criticism with Jurassic Park?

Answer 25

The speed of the T-rex was able to catch up to a jeep going really fast. Based on its size this is too fast. It would require way too much muscle. It could only go up to 30kph

Question 26

Study: Dinosaur max speed

Answer 26

Done with evolutionary robotics to make muscloskeletal models and compared to living creatures (as controls to see if their models were realistic). Predict T-Rex could max. do 30 kph