Exam 3: Part Two Flashcards
At the end of the Paleozoic era, what was a major event that happened?
Global mass extinction
What are two reasons the end of the Paleozoic is important?
- Reveals causes of mass extinction
- Leads to new kinds of life appearing, like dinosaurs
When did the supercontinent Pangea come together?
Late Paleozoic era (end of Pennsylvanian)
How did Pangea affect life (2 things)?
- Appalachian Mountains blocked rain from reaching the land
- Coal swamps are replaced by deserts (very dry climate)
What evidence is there for deserts in Pangea (3 things)?
- Sandstone in the cliffs
- Sand dune cross bedding that shows movement of sand over time
- Coloring= intense red color, very dry climate
T or F: Not all vertebrates lay their eggs in water.
True
What type of animals are amniotic eggs found in?
Reptiles, birds, and some mammals
The end of the Paleozoic era is also the end of the ______ period, which was ____ million years ago.
Permian; 252
every single member of a species dies
extinction
when many species go extinct around the same time
mass extinction
What are the Big 5 Mass Extinctions in Earth’s History?
- Ordovician Period
- One during Devonian
- One at the end of Permian
- End of Triassic
- End of Cretaceous
When did the biggest mass extinction in Earth’s history happen? What do geologists think caused this extinction?
- End of Permian; “Permian-Triassic Mass Extinction”
- Huge volcanic eruptions in Northern Asia
During the Permian-Triassic Mass Extinction, up to ___% of ocean species go extinct
95%
How did the Permian-Triassic Mass Extinction affect the following:
1. CO2
2. Global Temperature
3. Oxygen
- CO2: Increases
- Global Temp: Increases
- Oxygen: Decreases
What three periods does the Mesozoic era include?
- Triassic
- Jurassic
- Cretaceous
Is there life after Mass Extinctions?
Yes, bc if there were extinctions and we’re still here today, there must have been life after.
T or F: Groups that were dominant before a mass extinction are often rare or extinct after. (like things that were common, diverse, etc.)
True
a group of reptiles that include crocodilians, dinosaurs, and birds
archosaurs
What advantage did archosaurs have for surviving the Permian-Triassic extinction?
They have complex, efficient lungs that allow survival with less oxygen.
What were the first flying vertebrates?
pterosaurs (“pterodactyls”)
How was the environment and rocks during the Triassic period?
Seasonally dry, red rocks
What happened during the end of Triassic period?
One of the Big 5 Mass Extinctions; wiped out other archosaurs and helped dinosaurs become “big”)
What are dinosaur bones like?
Hollow, which is very bird-like –> points to their being a bird-like lung in dinosaurs
How long did dinosaurs last (how many years)?
160-170 million years long
How do we define dinosaurs? Are they all big, scaly, and extinct?
Dinosaurs are defined by their place on the reptile evolutionary tree. (they are a diverse group of reptiles)
They are not defined by size, scales, and being extinct.
If you include birds in the dinosaur group, the smallest dinosaur ever was a _________ _______.
bumblebee hummingbird
How can we recognize a dinosaur? (what’s in common with all dinosaurs)
All dinosaurs have a hole in the hip joint.
How can you determine what dinosaurs ate?
By looking at dinosaur teeth
What are the 3 major dinosaur groups?
- Ornithischians
- Sauropods
- Theropods
Which group of dinosaurs were two-legged meat eaters?
Theropods (ex: T-Rex)
What are two connections between birds and theropods?
- Both walk on two legs
- Both had feathers
What is Alabama’s only theropod egg called?
Ornithomimus
Which group of dinosaurs included the largest land animals of all time? What was special about their bodies that helped them get so big?
- Sauropods (ex: Brachiosaurus)
- Had long necks which helped them reach food high up in trees or low down in ground
What did sauropods eat?
plants
What did theropods eat?
mostly meat, some ate plants
Which group of dinosaurs chewed their food?
Ornithischians (ex: Triceratops)
What group of dinosaurs are most diverse in body size and shape?
Ornithischians
Do paleontologists consider birds to be dinosaurs? Why or why not?
Yes, because birds share many characteristics with their dinosaur ancestors, including feathers, wishbones, and hollow bones.
In what period was the earliest sign of birds (first birds showed up)
Jurassic
Birds come from _____ ancestors.
theropod (the two-legged meat-eaters)
What evidence indicates that some dinosaurs had feathers?
Evidence from feathers that were carbonized (fossilized feathers)
What is one example of a feathered theropod?
Microraptor
There have been carbonized feathers found in ocean ____ in Alabama.
shale
What are the three functions of feathers?
- Insulation (warmth)
- Display (like a peacock)
- Flight
What goes extinct at the end of the Mesozoic?
All non-bird theropods
What did Archaeopteryx have in common with modern birds and what did it shared with non-bird dinosaurs?
- In common with modern birds: feathers, wishbone, beak-like jaw
- Shared with non-bird dinosaurs: teeth, a long bony tail, clawed fingers on its wings
When did the supercontinent Pangea begin breaking up? Why do we look at the ages of the oceanic crust to understand the timing of the break up?
- During the Triassic period
- Because new oceanic crust forms at mid-ocean ridges as plates move apart (younger rocks in middle of ocean, older rocks at edges of ocean)
What are three reasons why the Mesozoic era is important?
- Shaping modern landscapes (Rocky Mountains)
- Climate and oceans (global temps and sea levels were very different back then)
- Energy resources (oil and gas)
T or F: North America is one of the last continents to join Pangea, and the first to leave (move away).
True
During the Paleozoic, North America was moving east, but when Pangea broke up, North America moved _____.
west
What is the connection between the break-up of Pangea and the rise of the Rocky Mountains in North America?
North America moved west during the break-up of Pangea → caused the Rocky Mountains to form.
What are the two main types of rocks found in rift valleys?
- Lava flows (volcanoes create lava flows; ex: Mt. Kilimanjaro)
- Immature sediment (because it’s more inland and had less time to deposit; hasn’t gone far from the source)
What types of rocks are found in rift valleys in eastern North America?
igneous rocks
During the ______ period, North America was completely torn apart from Pangea. What does this create?
Jurassic; creates new oceans
What is the connection between the break-up of Pangea and the formation of the Gulf of Mexico?
As the North American plate moved away from the South American Plate, a rift formed, which led to the opening of the Gulf of Mexico.
North America being pulled apart from Africa created what ocean?
Atlantic Ocean
If the Atlantic Ocean began spreading in the Jurassic, where should we find Jurassic rocks in the oceanic crust?
At the edges of the ocean
T or F: Ages of cooled magma chambers can give insight into precautions needed for future eruptions and what drives subduction during the Mesozoic.
True
_____ rocks show Mesozoic subduction.
Igneous
Where are dinosaurs likely to become fossilized and found because conditions there are good for fossilization?
Middle of North America, where there is Cretaceous sediment (Rocky Mountains)
How did the global temperature and sea level of the Cretaceous period (the last part of the Mesozoic) compare to today?
- Global temp: very warm climate; much hotter than it is today
- Sea level: since there were no glaciers, there were much higher sea levels compared to today.
How do the continents look at the end of the Mesozoic compared to today?
They look very similar to continents today.
What was underwater during the Cretaceous period?
North America
Oil and natural gas are energy resources from what type of rocks?
Marine sedimentary rocks
What evidence is there that the sea levels were high and continents were underwater during the Cretaceous period?
Marine rocks (especially limestone) on continents
What environment produces limestone? What type of water does this place need?
- Coral reefs
- Warm, tropical water
A majority of oil comes from _______ rocks.
Mesozoic
T or F: : areas that were underwater in the Mesozoic are some of the best oil producing places today.
true
How do oil and natural gas form? In what environment?
- Form from biological remains (dead sea creatures)
- Form in ancient oceans
What is the difference between oil and natural gas?
- Oil (or petroleum): is a liquid
- Natural gas: is naturally a gas (not gasoline; like air (ex: propane))
What is a similarity between oil and coal?
Both made from dead remains
What place is a big oil producing area?
The Gulf of Mexico
Cretaceous sea level reached up to ___ meters (820 feet) higher than today.
250
How did this ancient sea level (Cretaceous period) affect the Great Plains and coastal plain of North America? How do we know?
- Both the Great Plains and coastal plain were underwater.
- Evidence: lots of horizontal (flat) sedimentary rock layers in these regions.
How did the Cretaceous sea level affect Alabama’s geology and soils?
- Soil: Alabama was 2/3 underwater, which made it an area of nutrient-rich marine sediments that supports farming. (Sediment deposited made soil very fertile)
- Geology: Cretaceous period formed the Selma Chalk Formation in Alabama, which contains many fossils of marine organisms.
T or F: ocean sedimentary rocks are extremely valuable for farming)
true
ancient shoreline (basically the limit of where these cretaceous sedimentary rocks were deposited)
“fall line”
