https://www.mdpi.com/2571-550X/6/4/52
Published: 7 October 2023

Abstract
We examined lithic artifacts from the late
Neanderthal site Sesselfelsgrotte (Bavaria,
Germany) in order to evaluate the possibility
of fire use and intentional flint heat treatment
performed by late Neanderthals. We analyzed 1113
flint pieces from the G-layer complex (~60 to
45 kya; Micoquian) and 946 from the lower-layer
complex (~115 to 70 kya; Mousterian). Based on
macroscopic traits associated with the exposure
of flint to heat and fire, we assigned artifacts
to one of three groups: burnt, unburnt, and
possibly intentionally heated. Our results show
that while both complexes demonstrate the clear
presence of fire, fire is more common in the
younger G-layer complex. Moreover, possibly
intentionally heated pieces are significantly
more frequent in the G-layer complex, especially
among the tools and specifically among side
scrapers, suggesting a link between heat
treatment and the production of these tools,
most probably due to their functional and
cultural significance. We therefore suggest that
the flint in the G-layer complex of
Sesselfelsgrotte underwent intentional heat
treatment. The proportions of burnt flint
artifacts in both complexes suggest an
intensification in fire use at the site over
time, while the appearance of possibly
intentionally heated artifacts in the G-layer
complex suggests the development of this
advanced pyrotechnology by Neanderthals sometime
between these two timeframes. Our results are
supported by sedimentological and faunal data.
We view these results as further indication of
the advanced cognitive and technological
capabilities of Neanderthals, which did not
fall short of those of early modern humans.

"The upper G-layer complex (which includes layers
I, H, G5, G4, G4a, G3, G2 and G1) consists of a
series of archaeological horizons containing
approximately 85,000 lithic artifacts along with
abundant faunal remains, consisting mainly of
mammoth, reindeer, and horse remains."