The Panama Passageway: Using the PBDB to constrain the timing and extent of the The Great American Biotic Interchange

Callan Bentley
Northern Virginia Community College.
This activity is revised from a version by Ander Sundell (College of Western Idaho), who modified it from a version used by Tiffany Rivera (Westminster College), who modified it from an activity posted on the SERC site by Heather Wall (Syracuse University)
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Initial Publication Date: May 18, 2017 | Reviewed: December 10, 2020


Students learn how to use the online Paleobiology Database to map changes in the distribution of fossil vertebrates in the Americas through time. They will generate distribution maps for several key fossil groups and use these to estimate the timing of the development of the Isthmus of Panama (connecting North and South America).

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To be used in an introductory or intermediate undergraduate course, including (but not limited to) physical geology, historical geology, and paleontology.

Students can work as individuals or in pairs and class size can range from a small seminar (< 10 students) to a large lecture (> 100), as long as computer facilities are available.

Can be used with non-majors or majors from two or four year institutions. Each student or student pair will need access to a laptop or desktop computer connected to the internet, either running both Microsoft Word and an internet browser, or (if paper handouts are provided) simply running the internet browser.

This activity can be used in lecture, lab, or as a homework activity.

How much time is needed: 30-45 minutes total, depending on the level/breadth of discussion.

Skills and concepts that students must have mastered

Student should be able to:
- briefly describe the landscape changes that result from plate tectonic activity.
- describe the difference between terrestrial and marine organisms.
- outline the basic subdivisions of geologic time.

How the activity is situated in the course

It may be incorporated into a lesson on late Cenozoic tectonics. It could also serve equally well as a general case study of the role of tectonics in facilitating the migration (or isolation) of species.


Content/concepts goals for this activity

  • Gain familiarity with terrestrial mammals of the Cenozoic.
  • Gain familiarity with geography of the Americas.
  • Gain familiarity with the leading hypothesis for the linkage of the Americas via the build-up of the Isthmus of Panama.

Higher order thinking skills goals for this activity

  • Interpret showing the distribution of perissodactyls and glyptodonts for four different epochs of the Cenozoic Era in terms of their tectonic implications.
  • Test their interpretation with a suite of other relevant fossil organisms.
  • Test their interpretation with a set of relevant paleogeographic maps.
  • Apply these techniques to other regions, times, and species, and use the PBDB to test these ideas (though not necessarily conclusively).

Other skills goals for this activity

  • Use the Paleobiology Database to generate maps showing the distribution of perissodactyls and glyptodonts for four different epochs of the Cenozoic Era.

Description of the activity/assignment

Students use computers to access the Paleobiology Database Navigator and Ron Blakey's paleogeographic maps (at "Deep Time Maps") to evaluate the timing of the buildup of the Isthmus of Panama (and the connection of the Americas). The activity requires a web browser, so students should be reminded to stay on task and only visit relevant websites. Googling images of the animals in question is fine (glyptodonts are very cool to contemplate, for instance), but no one should be checking Facebook. The instructor may wish to demonstrate how to narrow down the results in Navigator by taxon and time period - using examples not relevant to this activity's focus - Cretaceous and Tyrannosaurus, for instance. A tutorial is available online at .

Determining whether students have met the goals

Formative assessment: If conducted in class, the instructor should walk around and mix troubleshooting advice with informal observations of whether the relevant time periods and taxa are being investigated.

Summative assessment: The four maps with two genera each (separate during the Oligocene and Miocene, beginning to mix during the Pliocene, and on both continents during the Pleistocene) and the conclusion that the Isthmus of Panama formed during the Pliocene are key summative assessment points.

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