Link: https://phys.org/news/2026-09-cave-glyphs-fresh-clues-teotihuacan.html

Research Article:
Christophe Helmke et al, Painted Teotihuacan glyphs of Cave 19, Chalcatzingo, Morelos, Mexico, Antiquity(2026). DOI: 10.15184/aqy.2026.10425 (Open access)

Snippet:

The cave, known as Cave 19, is in a region where people from the powerful ancient city of Teotihuacan established settlements and carried out rituals. The Teotihuacan Empire flourished centuries before the Aztecs and is known for its giant pyramids, culture and art. The images have faded over time, and some parts are now difficult to see with the naked eye.

[…]

In addition to filling in some missing details about these ancient rock paintings, the study could tell us more about Teotihuacan. For decades, experts have debated whether the symbols found on Teotihuacan buildings and pottery were evidence of a writing system or just decorative pictures. The new research at Chalcatzingo strengthens the case for a writing system. As the researchers note, "Teotihuacan writing can therefore no longer be dismissed or considered as a set of isolated or emblematic symbols."

It's an interesting find, but it still sounds like way too little to talk even remotely conclusively about a full fledged writing system.