Scientists discover why anacondas stayed giants for 12 million years Ancient anaconda fossils show that the snakes became giants soon after emerging in Miocene South America. Their size has stayed stable for over 12 million years, even though other huge reptiles went extinct. Surprisingly, warmer periods didn’t make anacondas bigger—just more widespread. Today they remain large thanks to surviving patches of ideal wetland habitat.
https://www.sciencedaily.com/r....eleases/2025/12/2512