Dinosaurs may have faced a dying world before the asteroid hit

Key Points:

• A new study from Johns Hopkins University using fungal spores in ancient sediments suggests that environmental stress and ecosystem decline began tens of thousands of years before the asteroid impact that caused the dinosaur extinction 66 million years ago.
• Researchers identified three distinct fungal abundance periods in rock samples from Colorado and North Dakota, with the earliest spike starting around 30,000 years before the asteroid strike, coinciding with massive volcanic eruptions in the Deccan Traps that likely altered global climate.
• The fungal spikes indicate widespread death and decay, supporting the idea that volcanic activity had already weakened ecosystems worldwide, setting the stage for the asteroid impact to deliver the final blow to dinosaur populations.
• A fungal bloom at the exact time of the asteroid impact was observed on multiple continents, reinforcing that fungi globally responded to the mass extinction event, while a later unexplained fungal increase 10,000 years post-impact highlights the unpredictable nature of ecological recovery.
• The study also proposes that mammals' warm-blooded physiology may have provided an advantage against fungal infections in the post-extinction environment, contributing to their survival and eventual dominance after the dinosaurs disappeared.