Meet the spike-toothed salmon, a prehistoric Pacific salmon 8+ feet long. With similarities to modern-day sockeyes, this giant species in the genus Oncorhynchus used to spawn in the Pacific Northwest as recently as 4-5 million years ago. What were its spikes for? Why did it go extinct? And is there anything we can learn from past extinctions? Three guests to help us reflect on this prehistoric branch on the salmon family tree: Ray Troll (artist), Kerin Claeson (professor of anatomy at the Philadelphia College of Osteopathic Medicine), and Brian Sidlauskas (professor and curator of fishes at Oregon State University).