Formation of Fossil Molds and Casts

Summary

Students will model in the lab, how fossil molds and fossil casts are formed.

Materials

• student lab sheet (attached)
• ½ cup plaster of paris
• plastic models of bones, teeth, and sea shells, (plastic fossils kit)
• 1 stick of modeling clay
• 100 ml beaker
• one stirring rod
• scalpels or scissors
• glue stick

Background for Teachers

Time required: One half period for each part of lab. End of one class period and the beginning of next period is suggested. Plaster of paris must dry overnight.

Notes to teacher: If the plaster of paris is too thin, the fossil casts produced will break apart as the student try to remove them from the clay. Clay must be soft for use in this lab.

Student Prior Knowledge

Students should be familiar with the processes involved in the formation of fossil molds and casts.

Instructional Procedures

1. Hand out worksheets and explain procedures and where material will be found.
2. Instruct students to label their materials for use the next day.
3. Allow students time to complete lab.
4. Summarize class results and ask students to make conclusions. (Data section).

Assessment Plan

Scoring Guide:
1. In the data-analysis section, each blank question is worth two points.
2. Each sketch is worth five points.

Use the answer key (attached).

Bibliography

Lesson Design by Jordan School District Teachers and Staff.