Neandertals took stick-to-itiveness to a new level. Using just scraps of wood and hot embers, our evolutionary cousins figured out how to make tar, a revolutionary adhesive that they used to make formidable spears, chopping tools and other implements by attaching sharp-edged stones to handles, a new study suggests.

Researchers already knew that tar-coated stones date to at least 200,000 years ago at Neandertal sites in Europe, well before the earliest known evidence of tar production by Homo sapiens, around 70,000 years ago in Africa. Now, archaeologist Paul Kozowyk of Leiden University in the Netherlands and colleagues have re-created the methods that these extinct members of the human genus could have used to produce tar.

Three straightforward techniques could have yielded enough adhesive for Neandertals’ purposes, Kozowyk’s team reports August 31 in Scientific Reports