2: Overview of Plant Evolution

Question 1

Cambrian to Ordovician (544-541 MYA

Answer 1

Tectonic activity
Reorganisation of continental plates
(volcanoes brought new soil
Ordovician started & ended with an extinction event
Time of dramatic sea level changes

Question 2

Sea Level Changes

1) Rises
2) Falls

Answer 2

1) warmed it gets the more ice melts on the poles and sea level rises
2) cooler more ice gets taken more water turns into ice at the poles and sea level falls

Question 3

Silurian (444-419 MYA

Answer 3

Dramatic sea level changes

First land plants emerged (Cooksonia

Question 4

Devonian (419 - 360 MYA

Answer 4

Laurasia & Gondwana drew closer together (plants spread)
Sea level high
Spore bearing trees by the end of period
Emergence of clubmosses, ferns, horsetails & progymnosperms

Question 5

Lycophytes / Lycopsids

(Identify

Answer 5

Clubmosses

Question 6

Pterophyta / Filicopsids

(Identify

Answer 6

Ferns

Question 7

Equisetales / Sphenopsids

(Identify

Answer 7

Horsetails

Question 8

Carboniferous (360 - 300 MYA

Answer 8

Pangea formed

Rise in sea level created inland seas and swamps (became coal deposits

Question 9

Permian (300 - 252 MYA

Answer 9

Seed plants dominated
Emergence of ginkgos, cycads & glossopteridaceae
Conifers evolved & started to radiate
Early (ice age), Late (Dried out)
Pangea 80% vegetative

Question 10

Triassic (252 - 200 MYA

Answer 10

Pangea drifted into Gondwana & Laurasia (mid period)
Period started & ended with mass extinction
Seed plants start to dominated (high atmos CO2)

Question 11

Jurassic (255 - 145 MYA

Answer 11

Laurasia (north)
Gondwana (south)
Arid continental conditions (no ice)
Confers flourished

Question 12

Creataceous (145 - 66 MYA

Answer 12

Angiosperms, (flowering plants), emerged at 140 MYA

Within 60 million year they attain ecological dominance due to their adaptive behaviour

Question 13

What drives evolution in plants

Answer 13

Changes in environmental conditions