Madtsoia bai

Madtsoia bai was a colossal primitive constrictor that dominated the river valleys and open woodlands of Eocene Patagonia. As the type species of the extinct snake family Madtsoiidae, it grew up to ten meters in length, overpowering native mammalian herbivores through powerful constriction before swallowing them whole. Its massive, robust vertebrae lacked the advanced cranial kinesis seen in modern boas and pythons, reflecting an ancient lineage that flourished across southern continents long after the non-avian dinosaurs vanished.