You will feel a lot more comfortable about going out for a swim or an afternoon boat ride knowing that such behemoths are extinct today!The Dunkleosteus is school bus-sized armored fish with razor sharp bladed jaws for cutting through anything in its path. The mighty Liopleurodon is a true monster, largest and most powerful of the Pliosaurs. The deadly Mosasaurs where the real sea serpents of their day, and some where large enough to dispatch an adult tyrannosaur easily.

The contests between predators and prey are the most dramatic events in nature. Taking an intimate and detailed look at the remarkable strategies employed by hunters to catch their prey and the hunted to escape. Sir David Attenborough narrates. "The Hardest Challenge" reveals the extraordinary range of techniques predators use to catch their prey - from a leopard using all its powers of stealth to stalk impala in broad daylight to wild dogs, whose tactic is to wear down their prey over long distances; from Nile crocodiles, the planet's most patient predators, to killer whales who use teamwork and intelligence to take on humpback whales. But even with these finely tuned strategies, the outcome is far from certain. Surprisingly, most predators fail most of the time.

The BBC's definitive television history of the rise and fall of the Nazis. The Nazis - A Warning From History exposes the popular myths surrounding the rise and fall of the Third Reich. The series explores how the Nazis came to power, how they ruled, how they treated their occupied territories and, above all, how a cultured nation could be responsible for such acts of inhumanity. How could a political party as fundamentally evil and overtly racist as the Nazis come to power? This remains one of the most enigmatic questions of the last century. Acclaimed historian Laurence Rees examines what led a cultured nation at the heart of Europe to commit the atrocities it did. In so doing, he exposes popular myths and encourages understanding of the real forces that led to one of the darkest chapters in modern history. Was it simply the hypnotic power of Hitler's rhetoric? Did the Gestapo really impose themselves by terror on an unwilling population? Through interviews with witnesses and perpetrators, along with archive film and records, this six-part series unveils a more chilling reality.

Professor Jim Al-Khalili sets out to discover whether nuclear power is safe. He begins in Japan, at the former Fukushima nuclear plant, where he meets some of the tens of thousands of people who have been evacuated from the exclusion zone. He travels to an abandoned village just outside the zone to witness a nuclear clean-up operation. Jim draws on the latest scientific findings from Japan and from the previous explosion at Chernobyl to understand how dangerous the release of radiation is likely to be and what that means for our trust in nuclear power.

Roses are red, violets are blue but according to the latest understanding these colours are really an illusion. One that you create yourself. Horizon reveals a surprising truth about how we all see the world. You may think a rose is red, the sky is blue and the grass is green, but it now seems that the colours you see may not always be the same as the colours I see. Your age, sex and even mood can affect how you experience colours. Scientists have unlocked the hidden power that colours can have over your life - how red can make you a winner, how blue makes time speed up. Watch an experiment where for people in a blue pod, a minute lasts 11 seconds shorter.

In 1927, Prohibition agent Eliot Ness narrowly escapes a hit ordered by Al Capone. Determined to prove to Capone that he's not intimidated, Ness and his team of Untouchables execute a series of high-profile raids on Capone's breweries. Over the course of a few months, they destroy more than 200,000 gallons of beer, worth a modern-day equivalent of $134 million - and the newspapers cover it all. Capone lashes out against Ness in the press. What Capone doesn't realize is that Ness and the Prohibition agents aren't the only ones trying to take him down. For the past four years, another government agency with more manpower and resources than Ness has been going after the infamous kingpin: the Internal Revenue Service.