Discovering that the world's oldest known spear points may come from a Homo heidelbergensis site is "like finding an iPod in a Roman Empire site," said paleoanthropologist John Shea, who wasn't part of the study. "It's that level of weirdness."

But it isn't weird to imagine these stocky big-game hunters using stone tools or even wooden spears in what's now South Africa. Until now, though, there's been no evidence H. heidelbergensis had the know-how to put the two together.

To fasten a handle to a blade—a technique called hafting—a prehistoric hunter likely would have had to procure a stone blade, a wooden shaft, twine woven from plants or animal sinew, and glue made from tree resin. The glue itself may have required a mastery of fire,