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

The working bit is produced by a side blow, which produces a very sharp cutting edge
with an acute angle. This efficient reduction-strategy is most commonly known for the
Acheulean hand axe, but is relatively complicated compared to normal biface-reduction
techniques. The bit resembles the less efficient celtiform uniface bit described above, and
has, for this reason been called an adze in some publications (Andrews and Rovner
1973:85). No examples of this form were found at Piedras Negras.
5.4.1.1.5: Large laurel leaf biface, thin (see Figure 5.2 #5). This type was manufactured
with a direct percussion technique. It is at least 12 cm long, and is symmetrical with
tapered points on either end of the biface. The proximal end, if one exists, is slightly
wider than the distal end, and may feature remnant cortex. The edges were often finished
with a pressure-flaking technique. A thin, lenticular cross section was a desired result of
the reduction process.
Whole examples and fragments of these tools are rare at the site, except in cache
contexts. They are made of fine- to medium-quality cherts and chalcedonies, and they
were used as knives or spearheads. Use-wear patterns suggest that they were often used
in both capacities. Since most examples of this form have use-wear of moderate-to-
intense cutting, the laurel leaf form may have been used as cutting instruments only after
its use-life ended as a spearhead, either through breakage or other cultural processes and
circumstances. The large laurel leaf, thin type was made using hard-hammer, and
possibly soft-hammer percussion 17 , but usually was finished with moderate pressure
flaking. The precise flaking-pattern of these bifaces may have required heat-treated or
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