Scientists discovered a fossilized blue-stain fungus from the Jurassic period in China, pushing back the earliest known record of these fungi by 80 million years. Blue-stain fungi are wood-colonizing organisms that cause discoloration in trees and can accelerate tree death when paired with wood-boring insects. This discovery reveals that these fungi and their relationships with insects evolved much earlier than previously thought, providing new understanding of ancient forest ecosystems and the evolution of fungal-insect interactions.