Two hundred million years ago, all of the
continents on Earth were joined in one large
supercontinent scientists call Pangaea. The
formation of Pangaea dried up many shallow
seas, which led to the evolution of new species
on land. This is the time during which mammals
first began to appear. During the Mesozoic
Era, around 190 million years ago, Pangaea
began to break up. The breakup resulted in
two landmasses: Laurasia, the northern group
of continents, and Gondwanaland, the southern
group of continents. Gondwanaland included
South America, Antarctica, Australia, Africa,
and India. By the end of the Cretaceous Period
65 million years ago, Africa and South America
had moved apart. By 43 million years ago, Australia
and Antarctica had separated and moved to their
present locations.
How do we know that these events actually
happened? You have probably noticed that South
America and Africa seem to fit together like
puzzle pieces. Because of this fit, many people
wondered if the continents once were joined.
A German scientist named Alfred Wegener proposed
that all of the continents once had been joined
in a supercontinent that he called Pangaea.
He suggested that Pangaea began to break apart
millions of years ago, and that the continents
continued to move until they reached their
present locations. He called his hypothesis continental
drift. Today, Wegener’s hypothesis
is known as the theory of plate tectonics.
Wegener was the first scientist to base his
hypothesis on more than the fit of the continents.
He collected data on rock formations, fossils,
and climates to support his hypothesis. Wegener
found the same rock formations and fossils
in Africa, South America, and Antarctica. Some
of the fossils were of species that grew in
only one type of climate, yet the fossils were
found on continents with differing climates.
How could there be fossils of tropical and
temperate climate species in Antarctica, a
continent that is permanently covered with
ice and snow? Have any fossils been found in
Antarctica that can support Wegener’s
hypothesis, and thus, the theory of plate tectonics?
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Your job in this WebQuest is to discover what
fossils have been found in Antarctica, and
to identify how those fossils either support
or disprove Wegener’s hypothesis and
the theory of plate tectonics. You will have
to find out what kinds of fossils have been
found in Antarctica. You will have to discover
how to interpret the meaning of these fossils
as indicators of the climate that once prevailed
in Antarctica. Finally, you will answer a set
of questions about the fossils of Antarctica
to demonstrate what you have learned.
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Look at the web sites given here to find the
information that will enable you to answer
questions about Antarctica fossils.
- Antarctic
Dinosaurs. At this site
you can learn more about the first dinosaur
fossils found in Antarctica, including
a Late Cretaceous ankylosaur found on
James Ross Island in 1986. Scroll down
to find out why so few dinosaur fossils
have been found on this continent.
- Fossils
From Mesozoic Era Antarctica. Go
to this site for a brief discussion of
continental drift (now called plate tectonics)
and how it affected Antarctica. There
is a good map of Antarctica here. Scroll
down to see an interactive graphic of
continental drift with a key to the continents.
Continue to scroll down to see a list
of fossils found in Antarctica.
- Antarctic
Summer - Fossils in Antarctica This
report by ABC News Online discusses the
issues surrounding fossils that were
found in Antarctica in 1978. Read the
report to learn what types of fossils
were found and what is being done to
preserve the exposed fossils that still
exist.
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1 class period for Internet research and answering
the set of questions
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Read through the following set of questions
before you begin your Internet research. As
you explore each site, look for answers to
the questions.
Questions about the Fossils of Antarctica
- What were the first fossils found in Antarctica?
Where and when were they found?
- What was the first dinosaur fossil found
in Antarctica? Where and when was it found?
- What dinosaur fossil was found on Vega
Island in 1986?
- What are the two reasons the fossil found
on Vega Island is of particular importance
to understanding the climate and location
of Antarctica millions of years ago?
- The first dinosaur fossil and the fossil
found on Vega Island in 1986 were representative
of what geologic time period?
- What dinosaur fossil was found in the Transantarctic
Mountains in the summer of 1990-1991? During
what geologic time period did this dinosaur
live?
- Besides the fossils already discussed,
name the other fossil animals that have been
found in Antarctica.
- Why have so few dinosaur fossils been found
in Antarctica?
- Early expeditions to Antarctica reported
on seeing fossils, but they did not collect
them. Who first reported seeing fossils of
leaves and stems of plants? Who reported
finding beds of coal near the South Pole?
- How do plant fossils and beds of coal support
the idea that Antarctica once was warmer
than it is today?
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In the process of completing this WebQuest,
you’ve become informed about the fossils
found in Antarctica, and what those fossils
tell us about the climate and location of Antarctica
millions of years ago. You have learned that
some dinosaur fossils found in Antarctica were
previously found only in the Americas. You
have discovered that some Antarctica fossils
were of species that could live only in temperate
or tropical climates. You have developed research
skills as you explored the web sites given
and identified the relevant information to
answer the set of questions above. Do you agree
with Wegener that Antarctica must have had
a warmer climate millions of years ago? Do
you think that the information you have gathered
about Antarctic fossils supports the theory
of plate tectonics?
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