Neogene Mollusk Communities

Author: Andrielle Swaby

Grades: University-level paleontology or historical geology class; adaptable for high school science classes.

Description: In this activity, students will investigate changes in the diversity of coastal mollusk communities during the Late Pliocene Epoch. Students will first identify which geological formations are aligned temporally. Then, they will assess a set of bivalve and gastropod genera found in three states: Virginia, Georgia, and Florida. By comparing and contrasting genera from the different samples, they will be able to:

  1. compare how diversity changes along the North American coastline
  2. use their knowledge of the life habits of major genera to understand what the environment was like in the sampled areas
  3. generate a sketch of what the ecological community might have looked like

Students should take away the following big ideas:

  • Diversity increases as you move closer to the tropics.
  • Understanding the ecology and life habits of fossil animals allows us to understand what the ancient environment was like.
  • As a general rule, bivalves are more numerous than gastropods in most mollusk communities.

Students should also learn how to collect data consistently from each sample, and graph their results in a bar graph format.

This activity uses the following terms and concepts:

  • paleoenvironment, paleoenvironmental reconstruction, paleoecology
  • taxa, species, genera, families, communities, species diversity, gastropods, bivalves
  • life history, life habits, infauna, filter feeders, deposit feeders, shelf environments
  • formation, member, Pliocene, organic content

Download files:

Student handout: PDF  Word

Instructor guide: PDF  Word