W1: L5 = Palaeo Ecosystem 3 [CPE] (Prof. Bamford)

Question 1

Results of the Permo-Triassic Mass Extinction? (2)

Answer 1

• Animal extinction.
• Plant extinction.

Question 2

Animal extinction attributes? (5)

Answer 2

• 98% Marine invertebrates.
• 85% Land animals.
• Mass volcanism then,
• Increased methane then,
• Global warming of 6 degrees.

Question 3

Plant extinction attributes? (3)

Answer 3

• Slow recovery in Early Triassic.
• Huge diversification in late Triassic Molteno Formation.
• Global.

Question 4

Plants extinct? (3)

Answer 4

• Glossopteris.
• Cordaitales.
• Arborescent lycopods.

Question 5

After the extinction? (6)

Answer 5

• Poor fossil record (fungal spkie/fern spike).
• Insects (generalist feeders survived, and specialists didn’t).
• Slowly new specialist feeders evolve.
• Fauna like Lystrosaurus survived, and few others.
• Fairly slow recovery of flora (Burgersdorp Formation).
• Current research of Trizygia & small Glossopteris leaves is in progress.

Question 6

P-Tr extinction attributes? (4)

Answer 6

• Ecological crisis (250Ma).
• Initial increase in plant diversity.
• Non-equilibrium vegetation dynamics.
• Most abundant species in undisturbed habitats are most susceptible to eventual extinction (complacent).

Question 7

Explain Non-equilibrium vegetation dynamics? (2)

Answer 7

• Time lag between initiation of collapse & selective extinction.
• Initial increase in regional plant diversity after ecosystem collapse (not a decrease as expected).

Question 8

CPE stands for?

Answer 8

Carnian Pluvial Episode.

Question 9

Carnian Pluvial Episode attributes? (6)

Answer 9

• Worldwide.
• Carnian.
• 4 episodes of increased rainfall.
• Repeated C-cycle perturbations (negative C-isotope excursions).
• Climate warming (from volcanism).
• Climate change led to major change in ecological communities.

Question 10

Thing to note about the CPE?

Answer 10

Conditions during this episode were the right conditions for speciation & diversification (that’s why you had a biodiversity explosion).

Question 11

Causes of CPE? (4)

Answer 11

• Wrangellia LIP volcanism (Alaska) then,
• Changes in ocean chemistry then,
• Temperature increased then,
• Four pluvial phases.

Question 12

Effects of the CPE? (6)

Answer 12

• Disappearance of 33% marine fauna.
• Origin of dinosaurs, crocodiles, lizards, turtles, mammals.
• Origin modern conifer families.
• Origin many insect families.
• Coal formation in N. hemisphere.
• Molteno (SA).

Question 13

CPE in South Africa attributes? (5)

Answer 13

• Molteno formation.
• Siltstones.
• 7 primary habitats (different habitats, well preserved).
• Diverse insect fauna.
• Only vertebrate footprints (no vertebrates around).

Question 14

List of the primary habitats? (7)

Answer 14

• Forest type 1.
• Forest type 2.
• Woodland 1.
• Woodland 2.
• Thicket.
• Marsh.
• Fern/Ginkgo meadow.

Question 15

Thing to not about the primary habitats?

Answer 15

There are specific insects for each habitat.

Question 16

Thing to note about CPE in South Africa?

Answer 16

Plants need acidic environments to be preserved, while animals need alkaline environments to be well preserved.

Question 17

Explain Siltstones point? (3)

Answer 17

• Fine grain sedimentary rock.
• Good preservation (lots of detail preserved).
• The finer the grain, the further the distance from its source.

Question 18

Formations found in the CPE? (2)

Answer 18

• Burgersdorp formation.
• Molteno formation.

Question 19

List of Burgersdorp formation flora? (4/7)

Answer 19

• Lycophytes.*
• Sphenophytes.*
• Ferns.*
• Early Dicroidium spp.*
• Ginkgoales.
• Cycadales.
• Some gymnosperms.
• Prioritise these.

Question 20

Molteno formation flora attributes? (2)

Answer 20

• Tremendous diversity of seed ferns & gymnosperms.
• Late Triassic.

Question 21

List of Molteno flora? (2/7)

Answer 21

• Dicroidium leaves (dominant).*
• Lepidopteris (leaves).*
• Ferns.
• Ginkgophytes.
• Cycadophytes.
• Gymnosperms (new families).
• Sphenophytes.
• Prioritise.

Question 22

Dicroidium (leaves) attributes? (6)

Answer 22

• Seed ferns.
• Upper Triassic.
• Distinctive cuticle (helps with identification).
• Dominant leaf type.
• Female = cupules.
• Male = pollen sacs underneath.

Question 23

Lepidopteris (leaves) attributes? ()

Answer 23

• Distinct cuticle that links to reproductive structures.
• Seed ferns.

Question 24

Ginkgophytes attributes? (2)

Answer 24

• Large trees with gymnosperm wood.
• No reproductive structures attached.

Question 25

Cycadophytes attributes? (3)

Answer 25

• Poor cuticle.
• Unknown reproductive structures.
• Rare.

Question 26

Ferns attribute?

Answer 26

• Variations in subspecies.

Question 27

Gymnosperms attribute?

Answer 27

Have compound structures.

Question 28

Podocarpaceae attributes? (2)

Answer 28

• Cones not attached.
• Evolved during the Triassic.

Question 29

Gondwana correlations to CPE? (4)

Answer 29

1) Molteno is in the middle of the huge Gondwana continent.

2) Wet climate, braided low velocity rivers & streams.

3) Fine grained sediments (good preservation for plants & insects).

4) S. America, Australia & India have similar floras, but use different names.