Teotihuacan was an immense pre-Columbian Mesoamerican city that thrived between the 1st century BCE and the 8th century CE, boasting a population of close to 150,000 inhabitants and some of the largest man-made structures in the Americas. Its stature and influence across Mesoamerica during its heyday was equally impressive as well. Distant Maya cities such as Tikal and Copan sought to have diplomatic relations with Teotihuacan. They called it Puh, or "Place of Reeds", a metaphor for a place of creation. When the Aztecs found its ruins five hundred years later, they were so impressed that they gave the city its modern name of Teotihuacan, the "City of the Gods". However, nobody knows the original name of the city. In fact, it is even unknown what language the original inhabitants spoke. More curiously, there is barely even a trace of a writing system in this enormously complex urban center.
The puzzle of Teotihuacano writing is compounded by the fact that they had extensive contact with nearby literate cultures. In fact, Mayas and Zapotecs immigrants lived in Teotihuacan, and both Maya and Zapotec texts have been found there. Yet Teotihuacanos did not develop a textual writing system. Instead, they had a stupendously complex iconography, which might have blurred into a highly iconic form of writing system. In fact, the meager examples of Teotihuacano writing are highly reminiscent of later Post-Classic Mixtec and Aztec writing systems, which were also non-textual and highly complementary with pictorial representation.
One of the main uses of Post-Classic scripts is naming individuals and geographical locations in painted manuscripts. The name of an individual is often placed next to his or her figure, whereas the name of a geographic location is infixed into highly iconic place glyphs.
One example of the naming of personages is from the murals of Techinantitla, one of the elite "neighborhoods" in Teotihuacan. These murals depict richly dressed individuals participating in some kind of ritual procession. Preceding each individual is a compound glyph that contains a constant element similar to the headdress of the individuals, and a variable element. In the following example, the variable elements are "goggles", raptor talons, and an arm with "reptile eye glyphs".
It it theorized that these glyph compounds are either names or titles of the individuals. The headdress glyph denote some kind of lordly or priestly status, and the variable component represents the role or the name of the person. The leftmost glyph is the "goggles" glyph, which is a symbol of Tlaloc, the rain and war god, perhaps representing a Tlaloc priest. The raptor talon might refer to a military order, such as the Eagle warriors among the later Aztecs. The arm with "reptile eyes" cannot be interpreted. It could be some kind of metaphor, or a phonetic rendering of the name.
Also among the Techinantitla murals are possible toponyms, or place names. These are in the form of variable glyphic elements inside plants that consist of entertwined roots of greenish color, trunks of red-brown color, and flowers that reflect part of the variable glyphs. The following picture illustrates three of these possible toponyms.
One argument for these compound glyphs serving as place names is the twisted root component as being a metaphor for a fixed location. A few Aztec place name glyphs do contain trees affixed with roots. Alternatively, it is possible that these place names are in fact trees. The cosmology of many Mesoamerican cultures describe trees holding up the sky and essentially serving as the vertical axis of the world. Perhaps the trees on these murals represent mythological Teotihuacano world trees, especially in their original context they were situated under a great undulating feathered serpent that could have represented the sky.
The most clearly defined examples of Teotihuacano writing is from the Plaza de los Glifos in La Ventilla neighborhood of Teotihuacan. These glyphs are painted on the ground of the plaza in a grid-like pattern. It has been suggested that these glyphs reminded people where to stand. The La Ventilla glyphs are interesting because they are devoid of accompanying paintings and are pure text. The following chart illustrates some of the glyphs from Plaza de los Glifos.
You will notice many glyphs sharing the same elements, such as the head of Tlaloc (the goggled-eye head) or the hummingbird. More often than not they are in combination with other glyphs. In fact, the way the glyphs are put together is in a manner similar to later Central Mexican writing systems. If the same principles apply, then the combinations could either be purely semantic, in that two glyphs are put together for their meaning; purely phonetic, in which two glyphs are combined for their sounds only; or one glyph functioning as the phonetic complement to a logographic sign in order to clarify the reading of the compound glyph.
There is also quite a bit of stylistic continuity between Teotihuacano and Aztec writing systems, as illustrated in the following chart. Please do note that the Aztec reading is by no means how the Teotihuacano glyphs should be read. A thousand years separate the two systems and it is reckless to use one to interpret the other. The Aztec glyphs and meanings are only to illustrate the similarity between both systems in sign style and in the way glyphs are combined. In fact we do not even know what language Teotihuacanos spoke. The most likely candidate language is an ancient form of Totonac, although there is also argument for Nahuatl as well. In other words, we cannot read Teotihuacano glyphs.
Teotihuacano writing should be considered a true writing system but one whose usage is non-textual and only restricted to naming people and places. The way glyphs can be combined suggest a productive system to create expressions in the underlying Teotihuacano language much like later Central Mexican scripts. However, unlike its contemporaries, the Maya and the Zapotecs, the rulers of Teotihuacan chose to use writing very sparingly in monumental settings and we are left with few examples. We can only guess what was the true nature of this script.