Lecture 22 - Dinosaur

Question 1

When was the mass dinosaur extinction?

Answer 1

65 million years ago

Question 2

What periods make up the Mesozoic era?

Answer 2

Triassic, Jurassic and Cretaceous

Question 3

A bipedal dinosaur needed a long tail for:

Answer 3

Locomotion

Question 4

What were dinosaurs?

Answer 4

Archosaurian diapsid reptiles

Question 5

What posture did dinosaurs have?

Answer 5

Upright posture with limbs under the body

Question 6

What are the three dinosaur groups?

Answer 6

Ornithiscia - Herbivores
Saurpods - Herbivores
Theropoda - Carnivores

Question 7

What is the classic interpretation of dinosaur relationships?

Answer 7

Ornithischia within their own group with bird hip characteristics.
Saurischian ‘lizard hip’: which included sauropods and theropods

Question 8

What is the modern interpretation of dinosaur relationships?

Answer 8

Ornithoscelida: Ornithischians and theropods

Sauropods by themselves

Question 9

What separates dinosaurs from other reptiles regarding their posture?

Answer 9

Dinosaurs have an upright posture unlike other reptiles that have their legs on the side of their body

Question 10

What are some different types of fossils?

Answer 10

Amber
Feathers
Skin impressions
Skeleton
Eggs
Footprints
Coprolites

Question 11

What do fossilised footprints and trackways allow use to estimate about an animal?

Answer 11

Allow use to estimate the leg length (due to imprint left and distance between imprints), body width (distance between imprints), and speed (distance between imprints)

Question 12

Obligate bipeds

Answer 12

Walked only on two legs, e.g., raptors

Question 13

Facultative bipeds

Answer 13

Walked on hind legs as a juvenile, transferred to four legs when adult e.g., Hadrosaurs

Question 14

Obligate quadrupeds

Answer 14

Stays on four legs for its entire lifetime e.g., sauropods

Question 15

A recent study discovered that a Spinosaurus had adapted what for aquatic locomotion?

Answer 15

Spinosaurus has adapted a large fin-like tail for propulsion

Question 16

How is the diet of dinosaurs determined?

Answer 16

Diet is inferred from the skulls and teeth

Question 17

A study by our lord Alistair Evans found Spinosaurus’ teeth had…?

Answer 17

Fine ridges on the teeth which correlate with aquatic feeding

Question 18

What were dinosaurs relationships with brain size?

Answer 18

They showed the general relationship between relative brian size and metabolic rate. Generally dinosaurs brain size was slightly larger than those of modern reptiles

Question 19

Encephalisation quotient in dinosaurs

Answer 19

Showed a similar range in mammals as in dinosaurs

Question 20

Do dinosaur bones have more similarities with reptiles or mammals?

Answer 20

They are more like mammals.
There is a higher proportion of remodelled secondary bone.
Bone remodelling may be due to great weight

Question 21

Did dinosaurs have low (reptiles) or high growth rates (mammals)?

Answer 21

Dinosaurs have high growth rates

Question 22

What does a dinosaur’s bone histology tell us about its relationship to reptiles and mammals?

Answer 22

A dinosaurs bone blood supply suggests more rapid metabolic processes than modern reptiles, more similar to modern mammals

Question 23

Are dinosaurs Endotherms or Ectotherms?

Answer 23

they are neither, dinosaurs fall in their own area called Mesotherms, which is in between both

Question 24

What is the evidence of group behaviour within dinosaurs?

Answer 24

Display structures
Sexual dimorphism
Allomorphic growth
Mass-death assemblages
Parental care and nesting behaviour
Multiple trackways

Question 25

What is some evidence supporting the Alvarez hypothesis (asteroid) in dinosaur extinction?

Answer 25

Iridium-rich time period
Faunal mass death
Fish contain spherules in gills
Exceptional preservation of plants, birds, fish, mammals and dinosaurs

Question 26

What would have been the major consequences of an asteroid impact 65 million years ago?

Answer 26

Reduction of photosyntheis
The layering of rare elements
Climate change
Extinctions