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

5.4.1.1.7: Large stemmed biface (see Figure 5.2 #7). The preform for the large stemmed
biface type was manufactured with a direct percussion technique. It was at least 12 cm
long. The proximal end features a finely crafted stem, which was shaped with a pressure-
flaking technique. The shoulders, or tangs, of the biface were notched by pressure flaking
or by indirect percussion. The margins were finished with a pressure flaker. A thin,
lenticular cross section was a desired result of the reduction process.
Few examples of this form exist at Piedras Negras, and none of the surviving
examples are complete. The fragments are often thin in cross section and finely chipped.
However, they are made from nonlocal flints indicating that they could have been made
outside of Piedras Negras. This form features small shoulders, and a somewhat tapered
stem (Figure 5.1). Other, more robust pieces have been found in a cave context near
Piedras Negras, and also from La Pasadita, which is a subsidiary site of Yaxchilan
located on the Guatemalan (eastern) side of the Usumacinta River (see Figure 5.2 #7).
These cave samples have more accentuated shoulders and may have been used for ritual
deposition rather than for cutting or hafting. Large stemmed bifaces are sometimes found
in Piedras Negras caches, but they were often notched to create different symbolic
meanings. In ritual caches, stemmed bifaces probably acted as markers of foreign
affiliation, since stems were not a common morphological trait at Piedras Negras.
Stemmed bifaces, especially those with accentuated “tangs,” may have been created to
imitate large, effigy atlatl points from Central Mexico (Hruby 2000). The large, basally
hafted, biface of choice at Piedras Negras was the large laurel leaf, thin type.
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