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Rare Space Rock Fueled Dinosaur Extinction
21 Sep
Summary
- A rare CO chondrite meteorite caused the dinosaur extinction 66 million years ago.
- Analysis of nickel isotopes narrowed down the impactor's composition.
- Fine debris, not sulfur, is now considered the primary extinction driver.
A rare type of meteorite, known as a CO chondrite, is now believed to be the space rock that caused the mass extinction event 66 million years ago. This celestial body, measuring 10 to 15 kilometers wide, struck what is now Mexico, leading to the demise of 75% of Earth's species, including non-avian dinosaurs.
Scientists analyzed nickel isotopes found in clay layers globally, which were deposited by the impact. This meticulous examination narrowed down the impactor's composition to a specific class of carbonaceous chondrites. The findings, published in Science Advances on July 17, 2026, suggest that fine debris ejected into the atmosphere was the primary driver of the extinction.
CO chondrites contain significantly less sulfur than other meteorite types, shifting the focus away from sulfur as the main extinction culprit. Researchers now point to the widespread atmospheric debris as the more likely cause. While the impactor's exact origin remains uncertain, its rarity underscores the unique circumstances of this catastrophic event.
