Paleolithic screw waterskin stoppers

These are the most delightful tools I have ever seen. They are from the Perigordian IV, which is 30 000 BP to 28 000 BP.  They are called 'goat skin corks' which have a hand cut screw thread!

As an archaeologist this doesn't surprise me too much although one doesn't expect to find a screw thread in the Palaeolithic ..

They are from two different sites, but the same time period. My bet is that both were made at one site, and traded to another. No two people come up with an intellectual leap like that independently, at the same time. It had to have been made by the same artisan or group of artisans, for sure. What is interesting, however, is that this was invented, but never became popular except in one general area at one time, about 30 000 years ago...

The one on the left is from Roc de Combe-Capelle, and on the right from Fourneau du Diable. They are both in the Dordogne area, about 90 kilometres apart.

Notice that they are both right hand threads, showing that right handedness in humans has been around for a long time - though we knew that anyway because of the differences in arms on the right and the left of skeletons...

The material of both is ivory. Hard to work, but it would be very durable...