Anthony Barnosky and Kaitlin Maguire Measure Mammal Extinctions at the John Day Fossil Beds

This video describes how prehistoric extinction rates are calculated from fossil data in a paleodatabase and compared to modern extinction rates.

Scientists Anthony Barnosky and Kaitlin Maguire travel to the John Day Fossil Beds National Monument to find, collect, and date fossils. John Day is an excellent location for collecting mammalian fossils spanning millions of years. Fossil data from the field is added to a massive paleoinformatic database, which can be used to determine when each species went extinct and to calculate the average, “normal” extinction rate for mammals. Based on this calculation, scientists have determined that the rate of extinction today is much faster than normal.

The accompanying “Student Worksheet” incorporates concepts and information from the video. The “Educator Materials” document includes key concepts, learning targets, questions, and responses.

An audio descriptive version of the film is available via our media player.