3.3 Million-Year-Old Fossil Sheds Light On How The Spine Evolved

It's hard evidence that the type of spinal segmentation and numbering found in modern humans emerged 3.3 million years ago, the scientists say. The remarkable fossil was discovered in Ethiopia. ...
http://www.npr.org/sections/thetwo-way/2017/05/23/529693497/3-3-million-year-old-fossil-sheds-light-on-how-the-spine-evolved