The Ancient Ancestors of Crocodiles: A Tale of Evolutionary Ups and Downs The notion that modern day crocodiles evolved from warm blooded species to cold blooded killers is a concept both fascinating and counterintuitive.
Our understanding of evolutionary biology often assumes warm blooded animals are physiologically superior, but the discovery of fossilized bones from 81 archosaur species suggests otherwise.
Fossil evidence indicates that crocodiles' ancient ancestors were likely warm blooded until at least 66 million years ago, when the Chicxulub asteroid wiped out most dinosaurs.