Dinosaur Environments

Question 1

When did plants appear and what plants were around by the time dinosaurs appeared?

Answer 1

Appearance of plants
1st plant fossil - middle part Ordovician
avascular spore plant
They were all spores

Question 2

When did Spore plants appear and where? What is the distinction between spores and plants?

Answer 2

Spores of plants ( mid Ordovician in SA)
Spores in water only until they come out of water, they were NOT PLANTS
Only plants when they were on land

Question 3

Most primitive (spore plant) probably belongs to

Answer 3

Hornworts or liverworts

Question 4

When did vascular plants first appear?

Answer 4

1st vascular plants: silurian

Question 5

What do vascular plants need to bring nutrients and waste up and down?
When did this evolve?
How do vascular plants bring things down?

Answer 5

Plants carry nutrients up and energy waste down through pits

For vascular system, it needs tracheid cells in the xylem
Happened in Cooksonia ( early Devonian )

Pressure gradient and gravity bring waste down

Question 6

Tall trees

Answer 6

(Late Devonian)
Spore plants
archaeopteris (like the bird it’s OLD)

Question 7

Tropical swamp forests

Answer 7

(Carboniferous)
Distributed near equator and tropics
Gigantic trees

Question 8

Carboniferous swamp and coals

Answer 8

Found coal where carboniferous swamp trees are

Question 9

Types of Carboniferous swamp trees

Answer 9

Horsetails (18 m)

Lycopods (Giant club mosses) (up to 35 m)

Question 10

Appearance of seed plants

Answer 10

Appeared in end of devonian/beginning of carboniferous and early Permian

Question 11

Climate of seed plants

Answer 11

Seed plants can survive dry climates

Question 12

Types/Examples of seed plants

Answer 12

Ginkos
Cycads (15 m)
Glossopteriids (fossil only)

Question 13

Vegetation behind dinosaurs

Answer 13

Dominated by conifers and cycads in most paleo reconstructions

Other plants (spore, vascular, and seed) were also there but these were just dominant

Conifers did really well

Question 14

Which new plant group appeared as dinosaurs evolved, in what form and when?

Answer 14

Flowering plants (early cretaceous)

Question 15

What are Flowering plants? How are they different than the other plants? (System wise)

Answer 15

Vasual system changed to vessel cells in xylem
Flowering plants changed from tracheid cells to vessell cells in xylem
mutation but the vessel cells do better at carrying the water up

Question 16

Amborella

Answer 16

Found in New caledonia
Only one known of its kind
Most primitive kind of flowering plants
No vessel cells yet

Question 17

flowering plants invaded water?

Answer 17

Most likely land flowering plants invaded water (evolved on land and then invaded water)

Question 18

Where did the flowering plants come from?

Answer 18

oldest fossil flowers are all aquatic plants

Question 19

Oldest flower fossil

Answer 19

montsechia

Question 20

Grasses

Answer 20

(flowering plants gave rise to grasses)

Mid cretaceous

Question 21

Grasses and how they affected teeth

Answer 21

Carried minerals (phytolith) fossils
These minerals erode the teeth b/c it’s abrasive so some animals would only have 1 generation of teeth

Question 22

Where were the land masses placed?

Answer 22

Pangea
Plate tectonics
Earthquakes happened on these curved shaped - plates
Plates are always moving, never stable

Question 23

How did the plate tectonics affect the dinosaurs?

Answer 23

Started with pangea, which broke gradually apart through age of dinosaurs
Continents moved, carrying dinosaurs but continents also broke apart, separating dinosaurs

Question 24

Pangea and the dinosaur period?

Answer 24

dinosaur period:

220 ma - pangea about when pangea was about to break apart

Question 25

Was the sea level high or low?

Answer 25

Sea levels were high, lots of shallow water, usually around tropics

Sea level higher than it was today

AT MOST 800 M above sea level (exxon) 
150 M (miller)

Question 26

Exxon and Miller curve

Answer 26

Exxon curve (black and blue lines researchers) and miller curve very different but still show around the same pattern
Most researchers believe miller curve more

Question 27

Relation between tropics, shallow water and plants

Answer 27

very productive for planet and plants

Question 28

North America and fossils

Answer 28

NA used to be divided into 3, thats why we find fossils in middle of US
Middle interior sea
CA under water so thats why we don’t find many fossils

Question 29

Sea levels as dinosaurs evolved

Answer 29

Sea levels started out low in triassic but gradually became higher and higher by time of dinosaur extinction

Question 30

What fluctuations of average temperature occurred through the age of dinosaurs?

Answer 30

Sea water temp (tropical probably) higher than ours
Big global warming spike before dinosaurs - extinction before dinosaurs
Mid cretaceous - steep heating
The declining slope - most diversity of dinosaurs until they were extinct
Sea levels high and warm
Always higher than now, but there was also a drop

Question 31

Whales appearing?

Answer 31

Whales appeared (eocene (peak) ) between paleocene and eocene
There was an Extinction but not big enough to say it was a mass extinction

Question 32

Oldest flowering plants (fossils included)?

Answer 32

Oldest flower fossil: montsechia
Archaefructus
Water lily