Thomas Tobin clears sand from around the fossil of a giant ammonite he found in 2009 on James Ross Island in Antarctica. (UW News)

The most-studied mass extinction in Earth history happened 65 million years ago and is widely thought to have wiped out the dinosaurs. New research indicates that a separate extinction came shortly before that, triggered by volcanic eruptions that warmed the planet and killed life on the ocean floor. This research was undertaken by ESSThomas Tobin, Peter Ward, Eric Steig and others. Read more about this exciting new finding!