THE FOSSILS OF ANTARCTICA Introduction 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? Top
Task 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. Top
Resources Look at the web sites given here to find the information that will
enable you to answer questions about Antarctica fossils. - Marine
Fossils from Antarctica. Visit this site for an overview of
the fossils found in Antarctica and what they reveal about the past
climate and geographical location of Antarctica. Scroll down to see
photographs of some of the fossils found on Vega Island, an island
just off the coast of Antarctica.
- 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.
- When
Dinosaurs Roamed Antarctica… Visit this site to read about
dinosaur and reptile fossils found in the Transantarctic Mountains.
These fossils are from the middle Jurassic, about 175 million years
ago.
Top
Time 1 class period for Internet research and answering the set of questions Top
Process 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?
Top
Conclusion 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? Top
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