Today we have five species of big cat, in the past there have been 30 and Nigel decides to rescue the most famous extinct prehistoric feline of all: the Sabre Tooth. Often referred to as the Sabre Tooth Tiger, this is incorrect as the creature was not a tiger but a big cat. Three million years ago the Smilodon, or Sabre Tooth, was top predator in North America and, when the landmasses of North and South came together, it entered the territory of South America’s top carnivore, the Phorusrhacid or Terror Bird: a three-metre tall flightless flesh eater!