topic 7 - extinctions

Question 1

what are the major mass extinction events and when did they occur?

Answer 1

Ordovician-Silurian Extinction: 440 million years ago.
Devonian Extinction: 365 million years ago.
Permian-Triassic Extinction: 250 million years ago.
Triassic-Jurassic Extinction: 210 million years ago.
Cretaceous-Tertiary Extinction: 65 million Years ago

Question 2

volcanism and basalt traps contributed to which extinctions?

Answer 2

Devonian extinction: Viluy Trap
Permian-Triassic: Emeishan Trap, Siberian Trap
Triassic-Jurassic: CAMP volcanism
Cretaceius-Tertiary: Deccan Trap

Question 3

what were the casual factors for the Ordovician-Silurian extinction?

Answer 3

the formation and then recession of glaciers across the Southern hemisphere

Question 4

what were the casual factors for the Devonian extinction?

Answer 4

A 32-mile-wide crater in Europe was created around this time, possibly suggesting a meteorite strike.

Question 5

what were the casual factors for the Permian-Triassic extinction?

Answer 5

• rapid global warming
• volcanism
• more gas emissions
• water is becoming very acidic
• photosynthetic shutdown

Question 6

what were the casual factors for the Triassic-Jurassic extinction?

Answer 6

• interruptions in the composition of the atmosphere by volcanic activity that occurred around this time
• masses began to split apart

Question 7

what were the casual factors for the Cretaceous-Tertiary extinction?

Answer 7

meteor !

Question 8

what marine groups were affected in the permian-triassic extinction? how did it matter

Answer 8

• 90% of the worlds oceanic organisms go extinct
• calcium carbonate exoskeleton (susceptible to ocean acidification)
• brachlopods, crinoids experience major loss of diversity
• rugose and tabulate corals, goniatitic ammonoids, eurypterids, trilobites completely lost

Question 9

what terrestrial groups were affected in the permian-triassic (PT) extinction?

Answer 9

• At least 70% of land vertebrates went extinct
• invertebrates: largest extinction of insects
• vertebrates: demise of almost all anapsids, large herbivores suffered most, 2/3 of labyrinthodont amphibians, seraphsids and therapsids lost
• some echinoderms survive, others dont

Question 10

how long did it take for diversity levels to reattain pre-extinction levels in the PT event?

Answer 10

7 - 10 million years

Question 11

what is the significance of skeleton type and mineralogy in the PT event?

Answer 11

exoskeleton and endoskeleton chemical composition matter!

Question 12

what happened to global climate during the PT extinction?

Answer 12

rapid global warming!!

Question 13

what happened to global climate after the PT extinction?

Answer 13

worked to achieve new normal

Question 14

what are the patterns in marine biodiversity in the Lower Triassic in NW Pangaea?

Answer 14

diverse fish, free-swimming arthropods, disoxiatolerant bivalves, arthropod-dominated refugia near deltas, organic mats in shallow water setting

Question 15

what are the patterns in marine biodiversity in the Middle Triassic in NW Pangaea?

Answer 15

diverse and abundant shallow marine assemblages, resurgance of “paleozoic faunas’, low diversity, low population density in offshore settings

Question 16

what are the patterns in marine biodiversity in the Upper Triassic in NW Pangaea?

Answer 16

return of true coral reefs, paleozoic-style coasts with strong ‘modern’ overprint (crinoid banks, brachiopods diminish in importance, bivalves much more common), offshore marine settings dominated by monotypic bivalve communities, most life up in water column

Question 17

what are some important characteristics that helped organisms survive the PT extinction event?

Answer 17

being small, mobile, anerobic sometimes (no need oxygen)

Question 18

WHAT MATTERS?

Answer 18

WHAT YOU WEAR (mobility, shut off breathing to go to oxygenated areas), WHERE YOU LIVE, SIZE (small)

Question 19

what marine groups were affected in the triassic-jurassic extinction? how did it matter

Answer 19

25-30% of marine life disappear
demise of conodonts
ceratitic ammonoids disappear
collapse of coral reef communities

Question 20

what different terrestrial groups were affected in the triassic-jurassic (TJ) extinction event?

Answer 20

• Large crocodile-like reptiles called archosaurs were wiped out, other than crocodylomorphs, pterosaurs and dinosaurs
• non-mammalian therapsids and temnospondyl amphibians had already disappeared ahead of extinction
• mammals largely unaffected
  plants spore turnover but most major groups survive

Question 21

who was not affected by the triassic-jurassic extinction event?

Answer 21

early mammals
most plants survive

Question 22

what were the major causal factors of the TJ event?

Answer 22

• interruptions in the composition of the atmosphere by volcanic activity that occurred around this time (CAMP)

Question 23

what dominated shallow marine succession for ~2 million years after the TJ extinction

Answer 23

siliceous sponges !

Question 24

what marine groups were affected in the end-cretaceous extinction? how did it matter

Answer 24

exception of crocodiles and marine turtles, no tetrapod weighing more than 25kg survived
- vertebrates: pletolosaurs and mosasaurs extinct, telost fish severe attack, 30% of sharks gone
- invertebrates: ammonoids and rudist bivalves extinct, inocermid bivalves trickle then disappear, 98% colonial coral, 60% all coral

Question 25

what terrestrial groups were affected in the end-cretaceous extinction?

Answer 25

• the end of the dinosaurs
• some archiac bird lineages demise
• demise of pterosaurs
• demise of same mammal linegaes
• loss of all large crocodile lineages
• 57% of plants

Question 26

who was not affected by the end-cretaceous extinction?

Answer 26

all extant mammal lineages
squamates minimal
amphibians minimal

Question 27

MAJOR EXTINCTION IN __________________ ____; MINIMAL AFFECTS IN __________ ________ AND __________ ______

Answer 27

TERRESTRIAL TAXA; BURROWIMG FORMS AND AQUATIC FORMS

Question 28

what major event occurs at the beginning of the EC extinction event?

Answer 28

chicxulub impact crater / tsunami

Question 29

how does chicxulub affect the worlds animal and plant populations?

Answer 29

dinosaurs gone, most plants lived

Question 30

where did chicxulub take place?

Answer 30

Yucatan, Mexico

Question 31

how did chicxulub affect north america?

Answer 31

The waves eroded shorelines and dumped reworked seafloor sediments throughout the area, from Chiapas in the southwest to Texas and Alabama to the north.

Question 32

what factors contributed to the EC volcanic event?

Answer 32

deccan trap
tanis locality -preserve things that were alive at one moment then dead the next