Almost exactly two years ago, on September 13 2013, Steven Tucker made the find of a lifetime. Deep in a cave system at the Cradle of Humankind his head torch revealed bones on the sloping floor of a cave.Tucker and fellow caver Rick Hunter were doing what they loved most: exploring the dangerous crevices and caves in the area around Maropeng.They were aware that they should be on the lookout for bones and, in the event that they found any, they should call Wits professor Lee Berger, the palaeoanthropologist who was researching hominid ancestors.They entered a crevice just 18cm wide, which led to a larger cave and then they climbed up what has been called "Dragon's Back" on the other side."We followed this crack down - this very narrow crack - I went down first. It opened up into this large section," Tucker said."Pretty soon after that we stumbled upon the fossils."I was the first to enter the Dinaledi Chamber [a name later given to the cave]. I called Rick down. He joined me down there. Within five minutes, we saw these bones in the floor."Two weeks later, they went to see Berger. " He didn't seem interested at first - but then he saw the jaw. He fetched a couple of beers and was super-excited. Those photos made him speechless."Tucker said he first thought they had found something interesting when he realised the bones were relatively large."We had another look at these fossils and eventually we found a mandible with teeth in it. That was the first thing we thought: This looks almost human." ..