The End of the Paleozoic Flashcards
For Exam 3, May 6th (16 cards)
How did increasing oxygen levels at this time (b/c of spread of plant life) affect insect size and why?
Insects got extremely big
Usually they stay small because they can’t increase surface area to increase O2 intake (you can’t just increase volume either)
However, since there was a lot of oxygen at this time, insects got big
What happened to C13 as tree become more prevalent?
C13 levels were increasing in the rock record b/c of more photosynthesis
We also see lots of carbon burial because of the plants, leading to even more O2 in the atmosphere
What sorts of climates were we seeing around this time? How did this shift as Pangea continued to form?
Rainforests were found globally, leading to cosmopolitan species
The formation of Pangea led to more interior continental deserts and the fragmentation of rainforests, which harmed amphibians and resulted in endemic species
Which is more likely to go extinct, an endemic species or a cosmopolitan one?
Endemic b/c they can only live under specific conditions and can’t adapt quickly to changes in said environment
What are fenestrae? What are extra ones good for?
Openings in the skulls like the eyes, nose, connection to spine, etc.
Extra holes near the mouth act as muscle attachment sites and allow room for muscles to flex, leading to a stronger bite force
What is a synapsid? A sauropsid?
How do they differ in their number of fenestae?
Synapsid = mammals (one extra opening)
Sauropsids = reptiles (two extra openings)
What is the difference between reptiles and amphibians?
Scales vs none, dry vs moist skin, hard-shelled eggs vs laying eggs in water
What is endothermy? Ectothermy?
Endo = warm-blooded
Ecto = cold-blooded
What happened to climate as the supercontinent Pangea formed?
Mass amounts of interior deserts, shrinking of coal swamps and rainforest areas, decrease in C13 and O18, rise in CO2, loss of ice caps, sea level rise, rise of ocean acidity, slowing down of thermohaline circulations
What was the Permo-Triassic Extinction?
The largest mass extinction in geologic history
Completely destroyed marine life and reefs
Lost all trilobites and almost all snails and octopi
Herbivores were hit hard
What sorts of animals were hit the hardest during the Permo-Triassic Extinction?
Things with high oxygen demands and calcareous skeletons (made of calcite, which is degraded in acidic water)
What caused the low oxygen levels in the Permo-Triassic Extinction?
Volcanic eruptions, indicated by large amounts of flood basalt discovered from this time
Lots of volcanic material and greenhouse gases = long-term warming
Eruptions ripped through coal beds, releasing CO2 and methane hydrates
How do volcanic eruptions affect climate in the short vs long term?
Short = cooling because of physical blocking of the sun by dust and ash (affects plants the most)
Long = heating because of greenhouse gases
How might the formation of Pangea have led to more volcanic activity?
Concentration of land mass acts like a weighted blanket that heats the mantle beneath it, leading to rising magma and more volcanic eruptions
How bad was the Permo-Triassic Extinction?
Up to 95% of all life on Earth died
There are some things you just can’t survive, even if you have the most beneficial traits possible
Summarize the order of events (starting with the appearance of animal fossils) thus far (i.e. end of the Permian)
First true animal fossils, biomineralization, Cambrian Explosion, GOBE, Mass Extinction, plants move to land, cooling climate, animals move to land, Pangea formation, Permo-Triassic Extinction
