Warm-climate preference helped crocodilians survive mass extinctions, new study shows

A team led by University College London paleontologists reconstructed the full evolutionary history of crocodilians, examining over 7,000 fossil sites and modern distribution data for species such as Florida alligators and Australian saltwater crocodiles. By overlaying these records on 52 global paleoclimate reconstructions, they discovered that crocodilians have almost always remained in warm, tropical or subtropical zones, moving poleward in warm intervals and back toward the equator during cooling phases.

The study highlights that this climate-tracking behavior, combined with physiological traits like low metabolic demand, aestivation and brumation, gave them a refuge during the Cretaceous-Paleogene impact, when sunlight reduction left most habitats unsuitable for dinosaurs. The research also notes the past diversity of crocodilian forms, from giant land predators to filter-feeders, underscoring how modern species are the remnants of a once highly varied group. Findings were published in Science Advances.