L6

Question 1

Interpreting morphology

Answer 1

• Making valid hypotheses is very reasonable
  • Principles are similar throughout time eg rainbows appear now, conditions were similar back then, so dinosaurs must have seen rainbows
  • Interpretation is a reasonable method as long as it is sensible and evidence based

Question 2

Part 1: Reconstructing the animal

Answer 2

• Reconstruct animal off anatomical knowledge based on nearest living relatives (crocodiles)
  • In situ specimens provide good evidence
  • Sliding up a phylogeny we can look at birds/ emus etc

Question 3

“Fleshing up” a dinosaur skeleton

Answer 3

• Not much soft tissue preservation so is challenging
  • Look at muscle attachment and anatomical knowledge

Question 4

Part 2: Reconstructing its capabilities, Biomechanics

Answer 4

• We can work out bone movement
  • Size of muscles mass/ strength etc
  • This is computer based
  • We use 3-D computer animation based on complex engineering algorithms
  • Finite strain analysis eg jaw strength
  • Multi-disciplinary

Question 5

Finite strain analysis can be used to work out what?

Answer 5

Jaw strength

Question 6

Trackways

Answer 6

• Lots of work has been done
  • Single print can work out foot structure etc
  • Evidence foot length is about a quarter of length from foot to hip, so can work out stride possibility
  • Can also work out dinosaur speed

Question 7

Dinosaur speed

Answer 7

6- 40 km/hr

Small bipedal theropods and ornithopods 40km

Large bipedal theropods and ornithopods 20km

Quadrepedal stegosaurs and ankylosaurs 6-8km

Quadrepedal sauropods 12-17km

Quadrepedal ceratopsians galloping 25km

Question 8

Intelligence of dinosaurs

Answer 8

• Sauropods are very low brain size to body size
  • EQ ratio of body size to brain size
  • Hunters had largest brain size
  • Flying dinosaurs have a large EQ (flying in three dimensional planes) Dromaeosauridae
  • Runaway evolutionary trajcetory

Question 9

What dinosaurs had the largest brain size?

Answer 9

Hunters

Question 10

Dinosaur senses

Answer 10

• Can look at eye socket size
  • Brain endocasts
  • Few endocasts available
  • CAT scan
  • Compare brain to similar anatomic relative
  • Can make some inferences about senses

Question 11

Dinosaur diet

Answer 11

• Reconstruct ecosystem based off rocks from the same time period
  • Pollen spores and plant fossils
  • Calculate a food-web

Gut contents

Question 12

Evidence for dinosaur diet (6)

Answer 12

1 Teeth form
2 Jaw adaptations
3 Co- occurence
4 Coprolities
5 Gut contents
6 Fortuitous finds

Question 13

Teeth form

Answer 13

• Crushing vegetation, vs serrated for eating flesh

Question 14

Jaw adaptations

Answer 14

• Reptiles cannot masticate and chew like mammals, they have inflexible jaws
  • Cheek and jaw can dislocate and go sideways so they can grind and swallow
  • Somewhat a chewing mechanism

Question 15

Co-occurence

Answer 15

Work out food webs

Question 16

Coprolites

Answer 16

• May be full of plant material or bones and work out diet
  • Tough to identify the producer of a certain coprolite
  • No complete certainty to know producer

Question 17

Gut contents

Answer 17

• Rare but very effective
  • Grasses did not evolve till dinosaur were extinct
  • Change in vegetation from tough to softer grasses

Question 18

Fortuitous finds

Answer 18

• Dinosaur predating another
  • Very rare
  • Landslide during attack, preserved attack

Question 19

Behaviour

Answer 19

• Tricky to get an understanding of
  • Nest burial of eggs
  • Fidelity due to burying in higher layers
  • Oviraptor was egg producer
  • Parental care can be detected from morphological development of eggs, can compare to crocodiles etc

Question 20

Parallel trackways

Answer 20

• Provide insight into herd movement
  • Often have hunter tracks following herbivore dinosaurs

Question 21

Sexual displays

Answer 21

• Sexual dimorphism
  • Also for sexual display
  • Male and female forms
  • Structures show communication

Question 22

Dinosaur physiology

Answer 22

• Adaptations work up to a ceiling limit
  • Very successful species
  • Large pressure upon its heart
  • Were at peak optimum size

Question 23

Evidence for dinosaur thermoregulatory physiology

Answer 23

Stance and activity levels
Adaptations for processing high volumes of food
Haemodynamics
Brain size
Nose morphology
Bone histology and growth rates
Predator- prey ratios
Palaeogeography
Core and peripheral temperatures

Question 24

Stance and acitivity levels

Answer 24

Bipedal requires less energy

Question 25

Adaptations for processing high volumes of food

Answer 25

- Have to consumer much more than cold blooded animals - Jaws and teeth

Question 26

Haemodynamics

Answer 26

Nodule

Question 27

Brain size

Answer 27

- Larger brains = larger energy expenditure - Energy requirements to fly are high

Question 28

Palaeogeography

Answer 28

- Dinosaurs lived at high cold latitudes suggesting they must be warm blooded

Question 29

Core and peripheral temperatures

Answer 29

- Warm blooded have consistent temperature everywhere - Isotope heat comparisons throughout the skeleton - Different degrees of warm vs cold-blooded Thermoregulation from feathers suggest warm bloodedness in dinosaurs

Question 30

Mysteries

Answer 30

- More depth in time the greater differences between LCA and dinosaur - More recent fossils may have more similarities Stegosaurs - Initially evolved as defence with spines - then evolved into plates for perhaps a different purpose

Question 31

Reconstructing a dinosaurs capabilities requires knowledge of?

Answer 31

Biomechanics Intelligence Senses Diet Behaviour Physiology