P. boisei, a distant cousin to modern humans, lacked a thick, powerfully gripping thumb characteristic of its hominid contemporary, Homo erectus (SN: 3/24/15), a prolific maker of sophisticated stone tools. But the newly described hand bones suggest that P. boisei gripped well-enough to make and use simple stone and bone tools, just as other members of the human evolutionary family may have as early as 3.3 million years ago (SN: 5/20/15). Stone artifacts are abundant at ancient Homo sites, a sign that our genus relied far more heavily on toolmaking than P. boisei did, says biological anthropologist Neil Roach of Harvard University, who wasn’t involved in the research.