Some archaeologists, such as Richard Diehl, argue for the existence of a Toltec archaeological horizon characterized by certain stylistic traits associated with Tula, Hidalgo and extending to other cultures and polities in Mesoamerica. Traits associated with this horizon are: The
Mixteca-Puebla style of iconography, Tohil plumbate ceramic ware and Silho or X-Fine Orange Ware ceramics. The presence of stylistic traits associated with Tula in Chichén Itzá is also taken as evidence for a Toltec horizon. Especially the nature of interaction between Tula and Chichén Itzá has been controversial with scholars arguing for either military conquest of Chichén Itzá by Toltecs, Chichén Itzá establishing Tula as a colony or only loose connections between the two. The existence of any meaning of the Mixteca-Puebla art style has also been questioned.
A contrary viewpoint is argued in a 2003 study by Michael E. Smith and Lisa Montiel who compare the archaeological record related to Tula Hidalgo to those of the polities centered in Teotihuacan and Tenochtitlan. They conclude that relative to the influence exerted in Mesoamerica by Teotihuacan and Tenochtitlan, Tula's influence on other cultures was negligible and was probably not deserving of being defined as an empire, but more of a kingdom. While Tula does have the urban complexity expected of an imperial capital, its influence and dominance was not very far reaching. Evidence for Tula's participation in extensive trade networks has been uncovered; for example, the remains of a large obsidian workshop.