Lesson plan: Fossilized dinosaur heart

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Objectives

Students will:

• Distinguish between ornithischian and saurischian dinosaurs.
• Identify traditional distinctions between reptilians and mammals focusing on heart physiology and metabolism.

Standards

National Science Education Standards

As a result of their activities in grades nine-12, all students should develop an understanding of biological evolution.

• The millions of different species of plants, animals and microorganisms that live on Earth today are related by descent from common ancestors.
• Biological classifications are based on how organisms are related. Organisms are classified into a hierarchy of groups and subgroups based on similarities, which reflect their evolutionary relationships. Species is the most fundamental unit of classification.

Benchmarks for Science Literacy

By the end of the 12th grade, students should know that the basic idea of biological evolution is that the Earth's present-day species developed from earlier, distinctly different species.

Suggested time

2-3 class periods, 45 minutes each.

Materials

CNNfyi article, "Heart of a dinosaur"
One piece of poster board for every three to four students
Pencil and paper

Procedures

1. Place students in small groups.

2. Using information from multiple sources, have half of the groups investigate the physical structure of saurischian dinosaurs and the other half investigate the physiology of ornithiscian dinosaurs.

3. Pair up each saurischian group with an ornithischian group and have them share information with each other.

4. In a class discussion, talk about the similarities and differences between the two groups.

5. Have students read the CNNfyi article "Heart of a dinosaur."

6. Then ask students:

• To which group, saurischians or ornithischians, do scientists believe this dinosaur belonged?
• Of what group of animals do many scientists theorize dinosaurs are an ancient ancestor? What physiological proof is there to support this theory?
• How does the information provided in the article affect that theory? Why do you think that some scientists might doubt the validity of this discovery?
• What key characteristics would confirm that the fossilized heart is more like a mammalian heart than a reptilian one?
• If the interpretation of the fossil proves to be correct, which previous understandings about dinosaur life and metabolism would change the most?

Assessment

Have students work in groups to create a chart that shows how the fossil could change the way we think about dinosaurs if the current interpretation holds up to scientific scrutiny. Give each group a sheet of poster board. Have students title their poster board "Dinosaur beliefs then and now." Have them draw a line down the middle and title the left side "Then" and the right side "Now." Have each group list at least four differences in the way we think about dinosaurs, citing previous thinking on the left and new thoughts on the right.