Dinasours

Question 1

What do fossil in the marine sediment reveal about extinctions ?

Answer 1

Major extinction events occurred numerous times

Question 2

Give the time period in which dinosaurs first evolved

Answer 2

The Triassic period

Question 3

What group of organisms lived alongside the dinasours in the Triassic period?

Answer 3

The Crurotarsi

Question 4

When did the crurotarsi go extinct ?

Answer 4

At the end of the Triassic, whilst the main dinosaur lineages persisted.

Question 5

Describe the theories of Crurotarsi extinction.

Answer 5

Thought to be outcompeted by dinosaurs
Actually morphologically distinct (D & C) No interspecific competition,
Due to another factor.

Question 6

When and why did the rapid increase in dinasour occur ?

Answer 6

83 million years, cretaceous

Evolution of flowering plants, new niche

Question 7

1000 species of dinosaur were thought to exist- actually synonyms,
How many actually exist ?

Answer 7

500

Question 8

How are the 2 dinosaur clades distinct ?

Answer 8

Due to hip morphology

Question 9

State the 2 dinosaur clades

Answer 9

Ornithschia

Saurischia

Question 10

Give the characteristics of the organisms in the Ornithischia.

Answer 10

Bird hipped croppers
All herbivorous
4 legged and bipedal species
Common after the jurasic.

Question 11

Give the characteristics of the organisms in the Saurischia

Answer 11

Lizard hipped dinosaurs

Theropods and Sauropodomorphs

Question 12

Define the characteristics of the Theropods

Answer 12

Within the Saurischia

Bipedal carnivores

Question 13

Define the characteristics of the Sauropodomorphs

Answer 13

Within the Saurischia
Quadrupedal herbivores
Long necked

Question 14

Which class to birds belong to ?

Answer 14

The Therepods, within the Saurishcia

Question 15

Give examples of feathered therepods within the fossil record

Answer 15

Microraptor
Archaeopteryx
Confuciusornis

Question 16

Why was the intital hypothesis of endothermy in dinosaurs unlikely ?

Answer 16

Large dinosaurs would require huge amounts of high quality food source to generate the type of heat required
Wasn’t present

Question 17

Why was the initial hypothesis of ecothermy in dinosaurs unlikely ?

Answer 17

Would require dinasours to bask as a means of thermoregulation
Could not be done in some habitats they inhabited.

Question 18

What is the proposed temperature regulation system of dinosaurs ?

Answer 18

Inertial homeothermy
Maintain a body temperature but is dependant on mass
Small- ecothermic
Large- Warmer, endothermic

Question 19

The larger the dinasour, the …… its body temperature

Answer 19

Warmer, even in same habitat

Gave different behaviours depending on size

Question 20

Give the main impacts of the meteorite strike

Answer 20

Lack of sunlight due to ash- affecting basking & food supply

Affect productivity of organism

Sex ratios- dependant on temperature In some species

Question 21

Give the 2 major pieces of evidence for meteorite impact

Answer 21

1. 180km wide crater in Mexico, fragments date 65 mya.

2. Global deposits of iridium common in asteroids, between cretaceous and later periods

Question 22

What occurred at the Deccan traps in India ?

Answer 22

Massive volcanic eruptions

Prevented photosynthesis and caused greenhouse effect altering temperature

Question 23

The Deccan traps or the Meteorite impact are thought to be the main reason the mass extinction

Answer 23

The Meteorite impact

Question 24

Did the competition with mammals affect extinction rates ?

Answer 24

No, mammals begun to diversify before extinction occurred. (good relationship)

Question 25

How did birds, crocodiles and mammals survive ?

Answer 25

Pure chance.