If “Lucy” wasn’t alone, who else was in her neighborhood? Key fossil discoveries over the last few decades in Africa indicate that multiple early human ancestor species lived at the same time more than 3 million years ago.
Here are some links :
http://www.pnas.org/content/113/23/6364.full.pdf
https://www.cmnh.org/pnas
http://www.heritagedaily.com/2016/06/lucy-had-neighbors-a-review-of-african-fossils/111617