• [History of life: Grades 6-8] Life forms of the past were in some ways very different from living forms of today, but in other ways very similar. (LS4.A)
• [History of life: Grades 9-12] Life forms of the past were in some ways very different from living forms of today, but in other ways very similar. (LS4.A)
• [History of life: Grades 13-16] Life forms of the past were in some ways very different from living forms of today, but in other ways very similar.
• [Evidence of evolution: Grades 6-8] Fossils provide evidence of past life. (LS4.A)
• [Evidence of evolution: Grades 6-8] There are similarities and differences among fossils and living organisms. (LS4.A)
• [Evidence of evolution: Grades 9-12] There are similarities and differences among fossils and living organisms.
• [Evidence of evolution: Grades 13-16] The fossil record provides evidence for evolution.
• [Evidence of evolution: Grades 13-16] There are similarities and differences among fossils and living organisms.
• [Nature of science: Grades 6-8] Scientific knowledge is open to question and revision as we come up with new ideas and discover new evidence. (P6, NOS3)
• [Nature of science: Grades 6-8] Scientists test their ideas using multiple lines of evidence.
• [Nature of science: Grades 6-8] Scientists can test ideas about events and processes long past, very distant, and not directly observable.
• [Nature of science: Grades 6-8] The real process of science is complex, iterative, and can take many different paths.
• [Nature of science: Grades 6-8] Science is a human endeavor. (NOS7)
• [Nature of science: Grades 9-12] Scientific knowledge is open to question and revision as we come up with new ideas and discover new evidence. (P4, P6, NOS3)
• [Nature of science: Grades 9-12] Scientists test their ideas using multiple lines of evidence. (P6, NOS2)
• [Nature of science: Grades 9-12] Scientists can test ideas about events and processes long past, very distant, and not directly observable.
• [Nature of science: Grades 9-12] Scientists may explore many different hypotheses to explain their observations. (P7)
• [Nature of science: Grades 9-12] The real process of science is complex, iterative, and can take many different paths.
• [Nature of science: Grades 9-12] Science is a human endeavor. (NOS7)
• [Nature of science: Grades 13-16] Scientific knowledge is open to question and revision as we come up with new ideas and discover new evidence.
• [Nature of science: Grades 13-16] Scientists test their ideas using multiple lines of evidence.
• [Nature of science: Grades 13-16] The real process of science is complex, iterative, and can take many different paths.
• [Studying evolution: Grades 9-12] Scientists use fossils (including sequences of fossils showing gradual change over time) to learn about past life.

• Disciplinary Core Idea LS4.A: Evidence of Common Ancestry and Diversity
• NOS Matrix understanding category 2. Scientific knowledge is based on empirical evidence.
• NOS Matrix understanding category 3. Scientific knowledge is open to revision in light of new evidence.
• NOS Matrix understanding category 7. Science is a human endeavor.
• Science and Engineering Practice 4. Analyzing and interpreting data
• Science and Engineering Practice 6. Constructing explanations and designing solutions
• Science and Engineering Practice 7. Engaging in argument from evidence

An excellent lesson for demonstrating and discussing the nature of science. Adaptable to multiple grade levels. A similar lesson has been developed entitled Xenosmilus.

Cut out the fossils beforehand and laminate them for extended durability.

Additional teaching tips for grades 9-12 and 13-16:
Point out that paleontologists often find single bones or even fragments of bones rather than sets of bones as we have in the activity.

Class discussion is an important part of this activity. Some questions to consider:
How did you decide how to arrange the fossils? How sure were you of the arrangements? How did this change when more fossils became available? Are there certain skeletal elements that are more revealing than others? Why? What can you conclude about the habitat that this creature lived in, about what it ate and how it obtained its food? What is your evidence?
You might ask your students to think about how confident they are that their hypotheses are correct. That would allow them to see that some hypotheses have better support than others, and why.

• Evidence for Evolution
• Nature of Science