The fossil record, which spans millions of years, contains large gaps while in some cases entire species have been described from just a few small pieces of bone.
Some religiously-inspired opponents of evolution theory use the patchy fossil record to argue that humans did not evolve from primates.
But rare fossil finds like the new skeleton from the Malapa caves in Sterkfontein, South Africa, give anthropologists the opportunity to gain huge insights into how our prehistoric ancestors lived and looked.
Africa is now widely accepted as the birthplace of mankind as simple primates evolved into the common ancestor we share with the great apes such as Chimpanzees and Gorillas.
With so few fossils, scientists have struggled to draw a definitive timeline of how human species evolved and arguments about how individual fossils should be ranked are common.
With an almost-complete skeleton, however, it will be possible to determine whether this early ancestor of humans climbed trees or lived on open grassland and if it stood upright or used its arms to assist when walking. Armed with this kind of detail, scientists should be able to make far more conclusive statements about how our own species evolved.