Neanderthals made or used 13 of nearly 600 wooden objects from a Spanish rock shelter

Thirteen out of nearly 600 is a little over 2 percent ^[15]. That low share is the most reassuring figure in the review. A rock shelter collects wood whether or not anyone shapes it, so a strict filter is what you want before reading anything into the remainder. The team's first job was to decide which pieces Neanderthals had actually used or made ^[5]. Most of what failed that test is trunks, branches, twigs, roots and accumulations of firewood ^[6].

The case the team then makes is about survival. "The archaeological record gives us a very biased picture of prehistoric technology. We see the stone because it survives, while a huge part of their material culture has simply disappeared," Josep Vallverdú said ^[8]. Chris Stringer at the Natural History Museum in London said the record of wooden artefacts has been "severely constrained" by the generally poor preservation of organic materials ^[10].

Abric Romaní got around part of that bias because of its geology. Much of its wood survives only as grain patterns in travertine, a calcium-carbonate rock that precipitates out of water in certain environments and kept the pattern after the timber rotted ^[3]. Charred artefacts and some actual timber add to the collection ^[4]. The conditions that saved these objects are also what make the site unusual, so it cannot stand in for an ordinary Neanderthal camp. "This is of course evidence from only one site, in one area, and one time span," Stringer said, "so it's just the tip of the iceberg in terms of a whole and mostly hidden technology that ran in parallel with the much better-known stone tools of the Palaeolithic." ^[13]

The review cannot say how much of the Neanderthal toolkit was wood. Mariana Nabais, also at the Catalan Institute, said that when a site preserves wooden imprints and charred objects, "it is almost like suddenly seeing the missing half of the toolkit" ^[11]. "Half" there is a figure of speech. The reported results do not set the 13 wooden artefacts against a count of stone tools from the same levels, so the proportion cannot be worked out from this site.

I think the survival argument holds up well here, and Stringer and Vallverdú make it in nearly the same terms from different institutions. The stronger claim, that much of Neanderthal technology was wooden, is the researchers' inference; one travertine site makes it plausible.

The collection spans about 22,000 years ^[14]. "We have evidence of woodworking across many archaeological levels and over thousands of years, and the objects are associated with very different activities: hunting, domestic tasks, containers and the organisation of living spaces," Vallverdú said ^[9]. Maria Gema Chacón said of the two spears: "Producing long, straight shafts and shaping them deliberately into pointed weapons required planning, skill and careful selection of the raw material." ^[12]