Ardipithecus ramidus
Until 1994, the oldest fossil of a possible ancestor of ours was a mere three and a quarter million years old,. Then some teams of excavators in Ethiopia’s Afar Depression began turning up pieces from some three dozen individuals, all from the same species of hominid, called Ardipithecus ramidus, and dated at 4,400,000 years Before Present. Of all those fragments by far the greatest number — 125 or so — came from a single female, not more than four feet tall and with a brain not a lot bigger than a chimpanzee’s, named for short Ardi.
Ardi doesn’t look exactly like a chimpanzee, though she’s (probably) furred and with a less jutting jaw than a great ape. If one of them were to turn up next to you at the pool, the most unexpected feature you would see would be the long, dexterous opposable big toe on each foot. This made it easier for Ardi to get around on tree branches, and that made it probable that she lived in a wood, rather than the soggy swamp that some Hollywood designers prefer to show.
