The third episode looks at the last generation of killer dinosaurs - carnivores that took killing to a new level. By the end of the cretaceous period - 75 millions years ago - these gigantic and specialised hunter-killers had spread throughout the globe. In the southern continents it was the powerful and muscular abelisaurids that reigned supreme but it was the famous tyrannosaurids (or tyrant dinosaurs) that dominated in the north. Whilst the northern daspletosaurus hunted in gangs, using its highly developed smell and hearing to take down opponents like the horned rhino-sized beast, chasmosaurus, in the Southern hemisphere the small-skulled majungasaurus reigned. And though the sharp toothed majungasaurus was an efficient killer of the much smaller feathered rahonavis that did not stop it from occasionally turning cannibal and hunting its own.
Isolated since the time of the dinosaurs, New Zealand's wildlife has been left to its own devices, with surprising consequences. Its ancient forests are still stalked by predators from the Jurassic era. It's also one of the most geologically active countries on earth. From Kiwis with their giant eggs, to forest-dwelling penguins and helicopter-riding sheep dogs, meet the astonishing creatures and resilient people who must rise to the challenges of their beautiful, dramatic and demanding home.
Helen looks at volcanoes. With shocking eyewitness footage of eruptions, and new thermal imagery and ultra-high speed photography, we can now capture on camera the complex processes crucial to understanding how and why these forces of nature erupt.
The NHK team that captured the world's first footage of a live giant squid in its natural habitat is setting out for another deep-sea adventure. They will give us a look at the amazing life forms with luminous bodies that have survived the harsh, pitch-dark deep sea environment of the Pacific.
In Herne Bay in Kent, Steve makes a jaw-dropping discovery of sharks teeth on the beach. Looking at how bad fatbergs are for the arteries of our seas. Plus we soar high over Mull with Sea eagles, and Chris meets a photographer who believes we have the best marine life in the world.