Test #2

Question 1

List the major sea level cycles (Sloss cycles) of the Paleozoic and during what periods they existed.

Answer 1

Sauk- Precambrian - early Ordovician
Tippecanoe- Mid Ordovician - the Early Devonian
Kasaskia- Mid Devonian - Mississippian boundary
Absaroka- Pennsylvanian boundary - Jurassic periods

Question 2

Explain the difference between the Flysch and Molasse phases of sedimentation during orogenies.

Answer 2

Flysch phases involve shales and turbidites (marine sediment) that are accumulated in foreland basins during mountain building. Molasse phases involve non-marine sediment deposited after the mountain has formed.

Question 3

Explain how trilobites prove the accretion of exotic terrains to the eastern margin of North America. Name the genus of trilobite.

Answer 3

During the Taconic Orogeny subduction was in the opposite direction than it currently is, which caused collision of igneous arcs with Laurentia. Trilobites and other fossils known only in specific exotic terranes are included in these areas which prove the landmass accretion. Peridoxies is the Trilobite.

Question 4

What type of basin formed on the eastern margin of North America during the Taconic Orogeny? Acadian Orogeny? When did these orogenies occur?

Answer 4

Taconic- peripheral foreland basin- Ordovician

Acadian- retroarc foreland basin- Mid/Late Devonian

Question 5

What is the difference between Stromatolites and Stromatoporoids?

Answer 5

Stromatolites are layered accretionary structures produced by cementation of cyanobacteria that show some of the most ancient records of life on earth. Stromatoporoids are sponges that were important to reef-building during the Ordovician.

Question 6

What are Sepkoski’s three evolutionary faunas?

Answer 6

1) Cambrian Fauna
2) Palaeozoic Fauna (Ordovician to Permian)
3) Modern Fauna (since Triassic)

Question 7

Explain the hypothesized causes for the two steps of the end Ordovician Mass Extinction.

Answer 7

1) The onset of glaciation caused extinction of many taxa because they were adapted to warmer conditions.
2) When the climate eventually warmed back up, many taxa that had adapted to the cool conditions died out.

Question 8

Explain why the Michigan Basin contains large amounts of evaporites during the Silurian.

Answer 8

Seas in the Michigan Basin had high saline content which flowed from North American inlets, which sank to the bottom of the seas. Sunlight and warm temperatures caused evaporation of the water and concentrated the salt. This salt was then “trapped” by reef banks around the edges of the basin.

Question 9

What was the dominant predator of the Silurian?

Answer 9

Eurypterids.

Question 10

Why do we see a wedge-shaped package of sediment thickest in the east that formed during the Devonian in New York State?

Answer 10

The Acadian Orogeny occured during the Devonian which formed a retroarc foreland basin. The flysch and molasse phases filled the basin with sediment. As you move westward, the basin thins out which causes its wedge-shaped appearance.

Question 11

List and describe two possible reasons for widespread black shale deposits during the Devonian.

Answer 11

1) Deep sea deposits: dying of reefs, below photic zone and stagnant water.
2) Worldwide increase of salinity by evaporation condition- petroleum source.

Question 12

What type of basin formed during the Acadian Orogeny?

Answer 12

The Acadian Foreland Basin is a retroarc foreland basin.

Question 13

How do the White Mountains of New Hampshire relate to the Acadian Orogeny?

Answer 13

The White Mountains formed during the Acadian Orogeny. The orogeny was the result of the collision between current day North America and Western Europe. The collision caused the crust to deform and uplift to form the White Mountains.

Question 14

What type of basin formed on the western margin of North America during the Antler Orogeny? When did this occur?

Answer 14

It formed an elongated peripheral foreland basin during Late Devonian and Early Mississipian times.

Question 15

When was the time period on Earth with the largest reefs ever?

Answer 15

Devonian.

Question 16

What types of brachiopods were dominant during the Ordovician? Silurian? Devonian? Carboniferous?

Answer 16

Ordovician- Orthids and Strophomenids
Silurian- Pentamerids, Strophomenids, Spiriferids
Devonian- Spiriferids
Carboniferous- Decline of spiriferids replaced by productides

Question 17

When did amonoids first appear?

Answer 17

First appeared in the early Devonian and died in the K-T mass extinction.

Question 18

What interesting patterns do we see with trilobite morphology during the Devonian? What might have been driving these patterns?

Answer 18

During the Devonian we see trilobites develope harder external skeletons which include spires. This is an adaptive response directly related to the rise of jawed predators that hunted them.

Question 19

Explain the evolution of jaws in fish.

Answer 19

Gill bars originally supported gills in primitive fishes. As fish evolved throughout Devonian the gill bars formed into upper and lower jaw support.

Question 20

What different types of fish were around during the Devonian?

Answer 20

We see a radiation of jawless fish in the Devonian. We also see Acanthodians, Placoderms, Ray-finned fishes. Transition from marine to freshwater habitats.

Question 21

What is the importance of the Gilboa Forest?

Answer 21

The Gilboa Forest, which is among the oldest forests in the world, burried and preserved fossils that are their only type on the planet.

Question 22

What major changes occur in the terrestrial environment during the Devonian?

Answer 22

The Devonian experienced the first significant adaptive radiation of terrestrial life. Extensive forests emerged, plants evolved roots, leaves, and the ability to bear seeds.

Question 23

What is the importance of the recently discovered fossil Tiktallik?

Answer 23

This fossil is representative of the transition from fish to amphibians. It developed adaptations to deal with the oxygen-poor shallow waters of its time.

Question 24

List and explain the differences between the major orogenies that formed the Appalachian Mountains.

Answer 24

1) Taconic Orogeny during the Ordovician- peripheral foreland basin.
2) Acadian Orogeny during the Devonian causing Euramerica to form.
3) Alleghenian Orogeny occured during the Carboniferous and Permian- Euramerica collided with Gondwanaland to form Pangea and finalized the Appalachian Mountains.

Question 25

Be able to explain a diagram of a cyclothem, specifically what types of sediment occur where in the cycle and what causes the observed patterns in sedimentation.

Answer 25

.

Question 26

Explain the process of coal formation.

Answer 26

Coal is formed by the compaction of plant material. Heat and further compaction remove water. Methanogenesis produces methane which ultimately removes hydrogen, some carbon, and oxygen. Dehydrogenation removes the hydroxyl group creating low-hydrogen coals.
Peat  lignite  bituminouse coal  anthracite + graphite

Question 27

What major taxonomic group dominated the sea floor during the Mississippian?

Answer 27

Crinoids.

Question 28

Explain the ecological variation seen in Carboniferous plants (what types of plants lived in what environments, i.e. wet vs. dry).

Answer 28

Lycopods dominated wet environments because they reproduced by means of spores. Cordaites used seeds to reproduced and could live in drier environments like forests.

Question 29

Why could insects attain such great sizes during the Carboniferous?

Answer 29

A spike in oxygen allowed insects to get as big as they possibly could given their biological structure.

Question 30

What is the age of the oldest reptiles?

Answer 30

Pennsylvanian.

Question 31

What evidence is there for a cool climate in the Lower Permian?

Answer 31

Glacial deposits in the lower Permian indicate cooler conditions. Also a worldwide decrease in sea levels show that there were colder temperatures.

Question 32

What major group of arthropods went extinct at the end of the Permian?

Answer 32

Triolobites.

Question 33

What are the three major Floras of the Permian? How are they related to latitude?

Answer 33

1) Euramerican- tropical/equatorial
2) Glossopteris- southern hemisphere
3) Siberian- northern hemisphere

Question 34

What percentage of marine taxa went extinct at the end Permian mass extinction?

Answer 34

90-95%

Question 35

What caused the two separate pulses of extinction at the end Permian?

Answer 35

1) Glaciation caused species adapted to warmer conditions to become extinct. The lack of water circulation also contributed during this stage.
2) Warming after the glacial period put stress on marine life. Also, species that had adapted to cooler conditions died off.

Question 36

Explain the importance of the Burgess Shale and Chengjiang faunas as they relate to our understanding of the evolution the major body plans of animals.

Answer 36

Organisms evolved when there was empty niche space- not much competition. They developed into very complex forms because of their lack of predators. This told us about Cambrian times.

Question 37

Provide three reasons for why animals evolved skeletons.

Answer 37

1) protection against ultraviolet radiation, allowing animals to move into shallower waters
2) prevent drying out in an intertidal environment
3) protection against predators

Question 38

What is type of animals is the oldest definitively known land-dweller and when did it exist?

Answer 38

Millipedes in the Ordovician.

Question 39

How was the Ouachita Orogeny different from the Alleghenian Orogeny?

Answer 39

Both took place during the collision of Gondwana and Laurentia. The Ouachita Orogeny formed as a westward continuation of the Appalachian Mountains, had an unusually deep foreland basin and consisted of deepwater black shale/flysch deposits. The Alleghenian Orogeny formed as an eastward movement, had a shallower basin and perpetuated the accumulation of molasse.

Question 40

What are Ostracoderms?

Answer 40

They are jawless fish which existed during the Ordovician and Devonian. One of the first species of fish and had a bony structure.