Functional Morphology

Question 1

How do we estimate speed of dinosaurs? (Physically and using what?)

Answer 1

Start w trackway - collection of footprints which records movement of an individual
Uses stride and pace

Question 2

Stride

Answer 2

distance between same side footprint

Question 3

Pace

Answer 3

distance b/t right footprint and left footprint

Question 4

Is speed correlated w/ stride length?

Answer 4

Yes, Use leg length and stride length and the line to estimate speed

Longer legs tend to be fast but also depends on stride length

Question 5

How do we calculate speed?

Answer 5

Uses leg length, hip height and stride length to calculate speed
Stride length / leg length
speed/ (leg length * gravitational acceleration)½
Use leg length and stride length and the line to estimate speed

Question 6

Are dinosaurs fast

Answer 6

Turns out dinosaurs not super fast

Most fast 8 mi/hr

Fastest known today (hip height 1.98 m)

Running 29.2 km/h
Walking 6.8 km/h

Question 7

Did T-Rex run?

Answer 7

T-REX are huge animals but bigger animals are slower than smaller
They require a lot of muscle just to stand b/c their normal standing position is kind of like in a squatting position

To run, a T-REX would need an extreme/impossible amount of muscle in legs
T-rex probably couldn’t run but b/c it was so big, it wasn’t slow

Question 8

Do footprints shapes indicate taxonomy only?

Answer 8

If the mud is super wet, when you step in it, your entire foot is submerged
When you take it out, it messes up the footprint

Footprints could preserve foot motions
variety of footprints depending by how soft the surface and the time the foot was in/on it
Footprint shapes from a single individual could very drastically so taxonomic applications require caution

Question 9

T-Rex biting and bone?

Answer 9

T-rex thought to be able to break down

Could bite bone but most likely their bone digestion was incomplete

Triceratops hip w t-rex bite marks
Models of the t-rex teeth were made and used cow models with same density like the triceratops to model how strong the bite was

Question 10

How strong is a T-Rex bite really?

Answer 10

Bite was front teeth

Front teeth less strong than back teeth
Measured to be 13,400 N for posterior teeth
Humans 749 N
Alligators 13300 N

So t-rex bite was similar to alligator
Did computer models -> 57158 N but probably not accurate since it’s such a high number

Question 11

Finite element analysis

Answer 11

3D model calculated that allosaurus not built to bite bone but skull is more robust than expected
Found out that
Allosaurus used jaw/teeth to shave off
Slashing using entire jaw as knife

Question 12

Power of a T-Rex skull

Answer 12

Could crunch hadrosaurus bone

Biting and tearing

Question 13

Broad crown

Answer 13

macronarians

Strong biting and tearing

Question 14

Narrow crown

Answer 14

(diplodocus)
Weak, not tearing
Picking at something soft

Question 15

Enamel and Dentine

Answer 15

Enamel more bitter so it fractures

Dentine doesn’t fracture but is easier to be worn down

Question 16

Lizard hips (Saurischia) and teeth

Answer 16

Thinner enamel, extra layer of interglobular porous space (IGS), more detine

Teeth of lizard hips/saurischian dinosaurs tough thanks to IGS

Question 17

What is interglobular porous space (IGS)?

Answer 17

IGS stops enamel from cracking, limits cracking to surface and not deep

Question 18

Why did Bird hips (Ornithischia) lose IGS?

Answer 18

Grinding down plants so if they had IGS it would be worn down too easily and they would get cavities

Bird hips got rid of IGS b/c it wears down too quickly when they process plants

Question 19

What is Nocturnal, diurnal based on?

Answer 19

based on feeding activity

Question 20

Nocturnal

Answer 20

night active

Question 21

Cathemeral

Answer 21

Eats in both day and night

Question 22

Crepsuscular

Answer 22

Sugar glider only dawn and dusk - crepusular

Question 23

Diurnal

Answer 23

day active

Question 24

What are elephants in terms of their feeding activity and why?

Answer 24

Cathemeral since big , heavy can easily overheat

Needs to eat a lot

Question 25

Reptiles - feeding activity

Answer 25

Reptiles more diurnal

Question 26

Mammals - feeding activity

Answer 26

Mammals more nocturnal

Question 27

Mammal + reptile + birds - feeding activity

Answer 27

Mammal + reptile + birds -> more diurnal

Question 28

Large animals - feeding activity

Answer 28

eat a lot
Daytime not enough to collect food
-> cathemeral -> Eats in both day and night

Question 29

Dinosaurs foraging in the dark?

Answer 29

Not many truly diurnal dinosaurs
Makes sense b/c they were big so many were cathemeral dinosaurs
Regardless of group, big plant eaters -> cathemeral
Large herbivores need to eat longer than in daylight

Question 30

How can we know what feeding activity dinosaurs had?

Answer 30

Can look at size of eye to see if they were nocturnal or not
>50% eye size nocturnal
<50% eye size diurnal
= 50% eye size cathemeral

Question 31

nocturnal dinosaurs?

Answer 31

Small theropod dinosaurs (meat eaters)

A lot of jumping /gliding animals are also nocturnal

Question 32

Velociraptor

Answer 32

Nocturnal or crepuscular

Question 33

Fighting dinosaur

Answer 33

Cathemeral
Nocturnal or crepuscular
Happened in dark or dusk

Question 34

Birds?

Answer 34

Archeopteryx - daylight feeder

Question 35

Pterosaurs?

Answer 35

Some pterosaurs were crepusular

(pterosaur) Rhamphorhynchus - low light feeder

Question 36

Did Allosaurus use its jaw like T-Rex’s? How did it use its jaw?

Answer 36

Allosaurus used jaw/teeth to shave off
Allosaurus: Slashing using entire jaw as knife
T-Rex: biting and tearing

Question 37

T-Rex and Allosaurus skulls?

Answer 37

T-REX skull is more robust than Allosaurus which is more slender

Question 38

How did Sauropodomorphs eat their food?

Answer 38

Sauropodomorphs did not grind plants. They just picked leaves and swallowed them whole