Module 11 Flashcards
(50 cards)
1
Q
- What is the greatest catastrophe the biosphere has faced since complex metazoan life evolved ~600ma?
- what triggered a cascading series of events? What happened to the global temp
- estimate of how many species became extinct?
A
- Permian-Triassic Mass extinction
- Extensive volcanic activity in Siberia, Causes global warming
-96% of all species on the plant became extinct
2
Q
Leaning Goals
1.Interpret oxygen isotopes.
2.Describe environmental conditions in the Early Triassic.
3.Explain the concept of ‘Disaster Taxa’.
4.Describe the possible causes of Early Triassic environmental conditions.
5.Describe the post Permian recovery.
6.List and describe the possible causes of the end-Triassic extinction;
7.Discuss what the sections that span the Triassic/Jurassic boundary in Haida Gwaii contribute to our understanding of the mass extinction at the end of the Triassic.
A
3
Q
- Pangea
- Panthalassa
A
-all land
-surrounded pangea “all sea”
4
Q
- early Tri climate?
- evidence
- ice at the poles? climate at poles?
A
-harsh, hot w/ arid desserts
- evaporates, red desert sandstone, ventifacts, calcretes
- no ice, relatively temperate, forest/ more diverse fauna could survive
5
Q
-when may have been the hottest, most arid time since life began to proliferate 600 million years ago?
A
early tri
6
Q
-conodonts and role in finding out Tri ocean temp
A
- worm like chordata in tri
- O isotopes taken from it
7
Q
what can we tell from equatorial deposits from South China?
- what temp and peak ~ when?
- what after?
-after that, when and name of that time, temp of water column (at equatorial)
-todays sea temp at equator
A
-it spans period covering end Permian to early Tri
-Show rapid warming ~36C peak ~252.1MA
- cooling following main extinction
- rise temp ~250.7Ma, late Smithian (part early Tri), 38C (maybe exceed 40C at equatorial)
- today <30C at equator
8
Q
what is “disaster taxa”
- abundance/diversity?
A
-Survive disasters
- high abundance but low diversity
9
Q
what is “disaster taxa”
- abundance/diversity?
A
-Survive disasters
- high abundance but low diversity
10
Q
Lystrosaurus
- poster child for ______?
- face shape?
- member what group meaning of name?
- member what wider group?
- what evolves form them?
- they where once the most _______ animals at that time
A
- poster child for disaster taxa
- face shape like shovel
- member dicynodonts meaning “dog like tooth”
- member wider group therapsids ‘mammal like reptiles’
- mammals evolve from them
- they where once the most abundant animals at that time
11
Q
Lystrosaurus
- when did it evolve
- when was it most abundant?
- it made up over ___% of terrestrial vertebrae species on earth
A
- evoved during permian
- most abundent early tri b/w 251-247 ma
- it made up over 90% of terrestrial vertebrae
12
Q
Lystrosaurus
- when did it evolve
- when was it most abundant?
- it made up over ___% of terrestrial vertebrae species on earth
A
- evolved during Permian
- most abundant early tri b/w 251-247 ma
- it made up over 90% of terrestrial vertebrae
13
Q
Lystrosaurus
- face shape
- eye placement
- teeth?
- diet
-use for tusk
- jaw movement
A
- face shape: short/ shovel like
- eye placement: high/forward on skull
- teeth?: none, had a beak like turtle used to shear off plant material
- diet: plants
-use for tusk: dig up roots/tubers, maybe for display - jaw movement: backwards and forwards, plant material ground down by a palate inside the mouth
14
Q
Lystrosaurus
- gait
- sturdy bones on forelimbs suggest?
- what features may have help it survive the extinction?
A
- gait: semi-sprawling like modern reptiles, not like mammals and most dinos
- sturdy bones on forelimbs suggest supported big muscles and indicate maybe burrower (maybe search roots/tubers), maybe make burrows to live
- help it survive the extinction: could get veg form surface and underground if times tough, generalist not specialist
15
Q
where forsets common in early tri?
A
no
16
Q
what type plants dominated early Tri
A
dominated by smaller herbaceous forms like Pleuromeia and Dicroidium (types of seed ferns) and perhaps by a few species of conifer.
17
Q
change river structure from Permian to Early Try
A
mainly meandering river systems in the Permian with banks stabilized by plants, to the common occurrence of a more chaotic braided system in the Early Triassic.
18
Q
Coal Gap
- when
- why
- when did coal appear again?
A
- Ealy Tri
- reduction in global flora links with an increased delivery of sediment to the ocean basins at this time
- appeared again ~ 15 million years after the end-Permian mass extinction
19
Q
Early Tri Oceans
- Disaster taxa that dominated
- coral?
- Only reef-like structure?
A
- brachiopod Lingula and the bivalve Claraia
- no corals, “coral gap” re-appeared mill yrs after start Tri
- Stromatolites: columns of cemented sediment created by mats of microbes, common before predators evolved in the Cambrian.
Since then, they are limited to the periods following mass extinction events, other than a few isolated communities that manage to survive in unusual environments where grazers are kept in check
20
Q
- Where did least amount organism live in early Tri?
- when is pattern particularly noticible?
A
- equator dead zone, opposite today where most diversity around equator
- pattern is particularly noticeable at that peak temperature rise at the end of the Smithian
21
Q
- what/what not was found at equator early Tri?
A
- in oceans fish, marine reptiles and corals are absent around the equator, life forms that are found tend to be invertebrates, in particular sessile mollusks, and stromatolite reefs
- similar on land with most fauna at poles
22
Q
Lilliput Effect (It is named for the tiny people Gulliver visited on his travels in the famous book ‘Gulliver’s Travels’ by Jonathan Swift.)
- most taxa in early Tri where ______ in size
A
smaller adult size/increased juvenile mortality rate
occurs as a response to rising temperatures.
result in a fossil record that is composed of smaller individuals.
probably also explains why trace fossils only record the presence of small organisms that were not really burrowing very deeply at this time.
- most taxa in early Tri where small in size
23
Q
- most extreme temp plants can survive in?
- why active creatures like fish, marine reptiles and cephalopods are absent or rare at the equator
A
- thermal tolerance for many plants about 35°C, with few being able to survive over 40°C
- more active you are the more active your metabolism and the more active your metabolism the greater your demand for oxygen.
24
Q
- how long does it take for earth biosphere to recover from normal extinction
- how long did take after Permian extinction?
A
- biosphere is well on the way to recovery within a few hundred thousand years
- Permian things were still pretty awful up to 5 – 7 million years into the Triassic
(only reason we are probably not registering another mass extinction at this time is that there is very little left to become extinct!)
25
what did high temp end Permian cause?
- reducing oxygen conditions (dysoxic or anoxic) in various parts of the oceans
- led to associated rise in H2S (euxinic conditions) due to the proliferation of certain sulfur loving bacteria
- increase CO2 levles -> more CO2 in oceans -> more acidic oceans
- many problems for creatures (like corals) that secrete a thick calcium carbonate shell or skeleton.
- bivalve Claria, that produced calcium carbonate hard parts, could only secrete shells that were very thin.
26
what maintained conditions beyond point expect them to last early Tri?
- still unclear
- proposed "smoking gun" Siberian Traps still active and release CO2, may be responsible for the increased warming at the end of the Smithian
- warming may have destabilized gas hydrates?
no evidence though
27
when did earth biota start to recouver?
- mid- late Tri, both marine and continental diversity increased and continue increase into Jur
28
- When do we see reefs again?
- main Paleozoic reef builders?
- evidence minor reef formation around when? what made it?
- when did stony/scleractinian coral make a comback?
-main reef formers today?
- reefs develop again mid Tri
- rugose and tabulate corals, extinct during the end-Permian extinction (took with them many invertebrates and vertebrates that lived in and around them)
- ~1.5 million years after the P-T boundary (by sponges and serpulid worms)
- 10 Ma after the extinction that stony corals really start to re-appear, Middle Triassic that we see the scleractinian corals appear in earnest.
- scleractinian corals that are still the main reef forming metazoans today
29
what invertebrate was common in the Permian
Brachiopods: resemble clams, but they belong to different group of animals called the lophophorates
feed using a lophophore which is a ring of ciliate tentacles that they used to capture material suspended in the water column.
30
what invertebrate was common in the mid Tri
mollusks like bivalves (clams) and gastropods (snails) that really recover and diversify
31
Mid Tri had the rise of what vertebrae?
rise of archosaurs, which by the Middle Triassic had started to replace the mammal-like therapsid reptiles like Lystrosaurus
in the form of the group “Rauisuchia” would rise to become the apex predators of terrestrial environments
resembling a crocodile but on long legs which were now tucked well below the body. They ranged in size from 4-6 m (13- 20 ft).
32
did dinos dominate Tri?
no, but were part of a rapidly diversifying vertebrate fauna
33
Coelophysis
- lived Triassic
- slender bipedal carnivore, about 3 m (9.8 ft) long
- common in the southwestern United States but it has been found worldwide
- probably an agile runner
- forward facing eyes giving stereoscopic vision and a good view of the road ahead that included good depth perception.
34
did Coelophysis live in groups?
One thousand specimens of Coelophysis were discovered at the Whitaker quarry in Ghost Ranch, New Mexico
speculation that may have roamed in large ‘flocks’.
This is difficult to prove however, possible that the creatures had gathered at this location to drink before they were overcome by a flash flood event.
It does show what a common and successful creature this little dinosaur was though.
35
Flying Vertebrates
archosaurs also move the vertebrates into a whole new area during the later Triassic, allowing them to get off the ground and soar into the atmosphere
36
First Mammals
earliest mammals evolved from some of those mammal-like reptiles (therapsids like Lystrosaurus) common in the Permian and earlier Triassic.
difficult to distinguish between the last of the therapsids (that were starting to look like mammals) and true mammals, but Late Triassic animals like Megazostrodon are certainly starting to look very mammalian.
37
1.What surprising finding was true of many species found in the Triassic?
2.What made some Triassic animals look like unrelated animals that lived much later?
3.What characteristics made Drepanosaurus look like birds?
4.Are the Drepanosaurus closely related to birds?
5.When does the rate of evolutionary change really take off? What is this phenomenon called?
6.What three examples are there of specific niches filled by reptile lineages?
7.What may have allowed the dinosaurs to survive the End-Triassic Mass Extinction?
8.What is it called in evolution when similar selective pressures lead to similar physical results?1
1. look like modern species but nit related at all
2. adaptive radiation/ convergent evolution
3. head/neck bird like
4. no, early reptile
5. after mass extinction, adaptive radiation
6. apex predator on land, catch fish, herbivore covered in boney armor
7. small/unspecialized
8. convergent evolution
38
- When was the Tri- Jur mass extintion
- what happened to the conodants? reef systems?
- estimated that ___% of all marine families, ___% of all genera, and an estimated ___-___% of all species would be driven into extinction
- 201.3ma
- conodonts extinct, reef systems hit again
- estimated that 22% of all marine families, 53% of all genera, and an estimated 76-84% of all species would be driven into extinction
39
Spotlight on Haida Gwaii
- Kennecott Point section demonstrates what? what's it cause by? what makes it useful for correlation purposes?
- what does Kunga Island provide?
- how doe the amonites fossils help in that area?
- Kennecott Point section demonstrates negative C13 isotope curve due to die off many photosynthetic organism, found sim age rock many areas of world
- Kunga Island provides radiometric data for TJ boundary by dating ash beds from the very latest Triassic part of this section
- ammonite faunas present in both sections allow us to tie our Haida Gwaii sections to those in other areas of the world through relative dating
40
1.Which specific fossil groups are found in the Haida Gwaii TJ Boundary sections?
2.Which fossil group is present in the sections in the latest Triassic that subsequently becomes extinct during the end-Triassic mass extinction?
3.What specific fossil group constrains the TJ Boundary most tightly in Haida Gwaii?
4.What is the lifestyle of the group discussed in Question 3?
5.Why does the Answer to Question 3 make this group a useful fossil to help define this boundary worldwide?
6.The ammonites are quite poorly preserved across this interval, so why are they so important?
1. radiolarians, amonites, conodants
2. conodants
3. radiolarians
4. lives on ocean floor
5. other fossils same age around the world
6. other fossils same age around the world
*check
41
- What happened to remaining therapsids and many of the Archosaurs in the TJ extinction?
- how about many of the large amphibians
- became extinct
- also when extinct
42
- What happened to remaining therapsids and many of the Archosaurs in the TJ extinction?
- how about many of the large amphibians
- became extinct
- also when extinct
43
- what caused the TJ mass extinction?
- alternate suggestions?
- falling sea levels, fragmentation of Pangea, rifts that formed the Atlantic Ocean were a center of major igneous activity
- meteorite, simply a decrease in diversity
44
TJ mass extinction
- why would falling sea levels a cause mass extinction?
(3)
- reason sea level change?
- reduced the area of shallow, warm seas, restrict spread of reefs, increasing competition in remaining reefs
- no more climate modifying inland seas, caused more extreme temperatures and seasons on land
- proposed that when deep water returned, it was low in oxygen, causing more marine extinctions
- reason for these sea level changes is uncertain
45
TJ mass extinction
- what was happening to pangea during Late Tri (3)
-significant rifts forming b/w the Americas and b/w Africa and Europe.
- Antarctica and Australia (sutured together) began separating from South America and Africa
- India began to rift from Gondwana and drift northwards
46
TJ mass extinction
- what igneous activity was happening?
- where is that evidence preserved today?
- rifts from forming Atlantic Ocean, lots hot magma introduced in that area
- preserved today in the New Jersey Palisades, along the Hudson River in parts of New Jersey and New York, where 100 – 170m (300 – 500 ft) high cliffs of basalt are visible
- part of CAMP
47
TJ mass extinction
- what is CAMP?
- when did it occur?
- produced how much magma?
- how long did it last
- Central Atlantic Magmatic Province (CAMP), included both the intrusive bodies of igneous rock like the Palisades and remains of vast outpourings of lava found today in NW Africa, SW Europe, N America.
- around time TJ extinction
- produced a volume of magma around 2-3 x 106 km3, covering an area of about 11 million km2.hickest deposits of lava today are found in the High Atlas of Morocco where flows can reach as much as 300 m thick
- All the CAMP material is estimated to have been erupted in a fury of activity, lasting only 40 000 years
48
TJ mass extinction
What other effects did CAMP cause (3)
- global cooling due to the release of SO2 and aerosols, followed by intense warming as CO2 levels started to rise in the atmosphere.
- warming may have also caused the destabilization and dissociation of gas hydrates in sediments on the ocean floor, releasing methane
- evidence of the spread of anoxic conditions in the oceans as oceanic circulation became sluggish, allow the spread of the sulfate reducing bacteria once again and release of H2S.
49
TJ mass extinction
- Where/ what is the 'eye of Quebec'
- when did it hit?
- now Lake Manicouagan
- impact Crater, 6th largest on earth
- 5 km asteroid (3.1 mi), crater was originally about 100 km (62 mi) wide, but has now been eroded down so it is only about 72 km (45 mi)
- central point is Mount Babel, formed due to post-impact uplift as the ground rebounded after the asteroid hit
- hit late Tri 12ma Before TJ extinction
50
TJ mass extinction
- other explanation decrease in diversity
- caused by decrease in speciation than by an increase in extinctions – a kind of slowing down of the engine of biodiversity as it were, with the normal rate of extinction not being met by a similar rate of new species evolving.
