Fungal infections don’t often make an appearance on this podcast, but when they do, you know you’re in for a wild ride. In this episode, we explore the rare but potentially deadly fungal infection blastomycosis. We trace the journey of Blastomyces spores as they depart from their cozy homes of decomposing wood and make their way first into mammalian lungs before possibly moving into the skin, intestines, and brain. How and why these fungi can be so deadly is our next stop, one that takes us into an unexpected direction: the fall of dinosaurs, the rise of mammals and the role that pathogenic fungi played in this transition. We delve into why comparatively few fungi are pathogenic to humans and how our warm-bloodedness may protect us. But, as we discuss in the episode’s conclusion, that protection may be weakened as our warming planet selects for fungi that can tolerate increasing temperatures. Dinos, dogs, deep time, and deadly outbreaks - this episode has it all.