A recent study challenges previous assumptions about recovery after mass extinctions, revealing that unique ecological roles may enhance survival during such catastrophic events.

Conducted by researchers from the University of Chicago, the Smithsonian Institution, and the Natural History Museum in London, the study analyzed thousands of fossilized clams and mussels from the end-Cretaceous extinction that occurred 66 million years ago.

Published in Science Advances on May 21, 2025, this research was supported by several organizations, including the National Science Foundation and NASA.

The insights gained from this study could inform modern conservation strategies for ocean ecosystems, which currently face threats from pollution and overfishing.

David Jablonski, a lead author of the study, highlighted the importance of understanding ecosystem recovery as the world confronts the potential for a sixth mass extinction.

Despite nearly 75% of species disappearing during the end-Cretaceous extinction, the study found that all ecological roles in ocean ecosystems remained filled, a finding deemed 'extremely statistically unlikely.'

Interestingly, the research indicates that survival does not guarantee future success in biodiversity, as some surviving groups did not diversify as expected after the extinction event.

The focus on mollusks, due to their abundance and fossilization potential, allowed researchers to gain a comprehensive view of pre- and post-extinction ecosystems.

The findings contradict prevailing models of biodiversity recovery, which either view extinctions as hastening inevitable changes or as defining events that shape future biodiversity.

Moreover, the unexpected resilience of ecological niches suggests that the survivors did not necessarily dominate or shape the new ecosystem as previously thought.