Arctic Dinosaurs (Oct. 2008)

Experts in Alaska investigate how dinosaurs managed to thrive in polar regions. Watch now (50 mins.)

The Four-Winged Dinosaur (Feb. 2008)

Surprising fossils from northeastern China spur a debate over how birds evolved. Watch now (50 mins.)

Last Extinction (Mar. 2009)

Scientists propose a radical new idea of what killed off mammoths and other large animals at the end of the Ice Age. Watch now (50 mins.)