• Students will be assessed on their general knowledge of plate separation and fault lines which caused the separation of Gondwanaland through their project presentations and whole-group discussion.

• Students will be assessed through whole group discussion on fossil location and why some fossils are on many different continents.

• Students will be assessed on whether Du Toit’s theory is true or false, based on the evidence they give in their project and presentation.

• Students will be assessed on their knowledge of maps and locations, as well as on their map presentation to the class. They will also be assessed on their presentation voice and clarity of speaking to the class.

Day 1

Begin the lesson by showing the class a standard physical map of the world. Tell students to look closely at the continents. Ask, “Do you think the continents always looked as they do on the map, or did they change shape or location throughout Earth’s history?” Write their ideas on a large sheet of paper or on the board.

Tell students, “In early 1915, the German scientist Alfred Wegener developed a theory that the continents once formed a giant supercontinent that he called ‘Pangaea.’ ” See the map of Pangaea (S-8-6-1_Pangaea.doc).

“He speculated that Earth took this form about 245 million years ago, during the Triassic period of the Mesozoic Era. (The Mesozoic is the era in which dinosaurs lived.) A few years after Wegener proposed his theory, South African geologist Alexander Du Toit further theorized that Pangaea divided into two supercontinents 205 million years ago. Du Toit called the northern supercontinent Laurasia and the southern one Gondwanaland. The scientists used many kinds of evidence to advance their theories. They found similar fossil remains of plants and animals on different present-day continents. The scientists hypothesized that the continents were once connected.”

Ask students, “If you follow steps similar to those of Wegener and Du Toit, will you see fossil evidence that supports the theory that one supercontinent was divided?” Hand out copies of the Prehistoric Land Masses activity sheet (S-8-6-1_Prehistoric Land Masses.pdf). Tell students they will focus on Gondwanaland, the supercontinent that includes South America, Antarctica, Australia, Africa, Madagascar, and India.

Tell students that they will map the locations of four different fossils:

• Glossopteris: A fern found on the southern continents

• Cynognathus: A land reptile found in South America and Africa.

• Lystrosaurus: A land reptile found in Africa, Antarctica, and India.

• Mesosaurus: A freshwater swimming reptile found in Africa and South America.

Students should mark these locations on the sheet, using the map key code.

Tell students to cut out the continent shapes and try to piece them together as Gondwanaland. Ask them to think about how the different shapes fit together. For homework, have students paste their finished version of Gondwanaland on the Prehistoric Land Mass activity sheet.

Day 2

During the next class period, have students share their versions of Gondwanaland.

“Are most constructions similar?” Show students a picture of what scientists believe

Gondwanaland looked like (S-8-6-1_Gondwanaland.doc).

Ask students, “Knowing where the fossil remains have been found, does this evidence support Wegener and Du Toit’s theory? Do you think it is sufficient evidence? What other information would be helpful?” Tell students that over the past century, scientists have continued to find evidence supporting this theory.

Extension:

For the whole class, common Pennsylvania fossils can be reviewed through group discussion. Questions on why certain types of fossils may have been found in Pennsylvania can be raised as well as other questions relating to geographical location and biological diversity. See http://www.dcnr.state.pa.us/topogeo/education/es2.pdf

• For students going beyond the standards:

• Have students develop a geologic time line showing when scientists think that Pangaea broke up, when Gondwanaland and Laurasia formed, and when Gondwanaland separated into the continents as we know them today. See the Related Resources section for Web sites providing more information.
• The work of Wegener and Du Toit provided the foundation for the theory of plate tectonics, which was developed in the 1960s. What other information came to light that helped scientists develop this theory? Make a poster showing the progression of discoveries and name the scientists who were involved. Use the Web sites in the Related Resources section, as well as earth science textbooks, to find more information.

• For students requiring more practice with the standards, the following accommodations can be implemented:

• Have pieces and notes cut out and available for students beforehand.
• Have questions available or on overhead for students to have in front of them so they can have a visual copy for themselves to look at and process.
• Let students do the research and maps on a computer.
• Break lesson up into a three- or four-day unit with more explanation and time for students to process and understand vocabulary and standards of Pangaea and Gondwanaland.