The Organization of Chipped-Stone Economies at Piedras Negras ...

The goal of reduction would be to produce a workable blank for thin or thick bifaces and
unifaces. Many late-stage, nodule reduction flakes were used as knives and scrapers.
5.6.2: Biface- and Uniface-Reduction Flakes
Biface-reduction flakes are separated into early-, middle-, and late-stage reduction
flakes. Early-stage biface-reduction flakes feature few flake scars, or facets, on their
dorsal surfaces (usually two or three) and the platforms are not very complex with only
two-to-three facets. Early-stage biface-reduction flakes are likely to have cortex
remaining on the dorsal surfaces. Middle-stage biface-reduction flakes are less likely to
have cortex, but depending on the size of the nodule, cortex may be evident at all stages
of reduction. Middle-stage biface-reduction flakes often feature multiple percussion scars
on their dorsal surfaces, and the platforms tend to have more facets (>2), but like early-
stage flakes, the platform-to-dorsal surface angle usually is quite wide. Late stage biface-
reduction flakes are often thinner, look “more refined,” and have multiple flake scars and
platform facets. The frequency of remnant cortex is quite low, but, nevertheless, extant
on some specimens. Indeed, many finished bifaces and unifaces retain cortex on their
surfaces, often at the distal end of the tool.
Biface-reduction flakes are separated into three size categories, which are roughly
based on their length: Large (>7 cm), Medium (5-7 cm), and Small (