Overview
- The UCL-led study published in Science Advances in October 2026 combined more than 7,000 fossil occurrences, a phylogeny of over 400 species, about 130,000 modern locality records, and dozens of paleoclimate reconstructions to map habitat suitability across 245 million years.
- Researchers found crocodile-line archosaurs repeatedly tracked warm, low-latitude climates instead of evolving broad cold tolerance, expanding toward the poles during past hothouse intervals and retreating to the tropics during cooling.
- Post-impact climate experiments run by the team show that under nearly all modeled Chicxulub scenarios equatorial and subtropical zones remained suitable for these animals, and only an extreme 15% drop in sunlight removed suitable climate globally.
- The study cites biological traits that likely aided survival, including low metabolic needs from ectothermy, the ability to enter dormancy, semi-aquatic habits that buffered food supply shocks, smaller body sizes, and generalist diets.
- Authors warn that if past persistence depended on shifting ranges to follow warm climates, ongoing habitat loss from roads, farms, and cities could block similar movements and worsen extinction risk for modern cold‑tolerant species.