S1, E1: The extinction of the dinosaurs left a power vacuum. Enter the dragons: powerful modern reptiles which still dominate large areas of our planet. This show reveals how crocodiles, giant lizards, monster turtles and venomous snakes outwit warm-blooded birds and mammals, and asks which ones we still need to fear. Ruling Reptiles goes in search of the modern reptiles which have inherited the dominant role once held by the Dinosaurs. Most of the 8,000 reptile species alive today are predators. Crocodiles are ambush specialists, armed with massive, tooth-studded jaws and an amazingly efficient system of temperature-control. They effectively control the water supply of tropical rivers and lakes, exacting a tax in flesh from thirsty animals. Giant tortoises and turtles are protected by a tough shell which acts as a mobile home, allowing them to thrive in some of the world’s most inhospitable terrains. Marine turtles grow to a huge size and have conquered the world’s oceans. The dragon-like monitor Lizards are adept at climbing, running, swimming and digging, and armed with a ferocious bite. The mighty Komodo dragon co-operates with deadly super-bugs to poison its prey, while the gila monster has developed venom as a chemical weapon. Some snakes’ venom is so deadly that just the sight of a snake can strike terror into most other animals, including us. Could fear be the greatest of all reptile weapons?