A large number of languages known only from brief mentions are thought to have been Uto-Aztecan languages, but became extinct without being documented. The following list is based on.
Giamina/Omomil: Kroeber and Lamb believe Giamina may constitute a separate branch of Northern Uto-Aztecan, although Miller is uncertain about this. It was spoken in Southern California.
Colotlan: a Pimic language closely related to Tepehuan, or Teul and Tepecano
Comanito: a Taracahitic language closely related to Tahue
Concho: probably a Taracahitic language. Subdivisions include Chinarra and Chizo; Toboso is possibly related to Concho as well.
Conicari: a Taracahitic language closely related to Tahue
Guachichil: possibly a variant or close relative of Huichol
Guasave: possibly a Taracahitic language, or may instead be non-Uto-Aztecan language possibly related to Seri due to the speakers' maritime economy. Dialects include Compopori, Ahome, Vacoregue, and Achire.
Guazapar : probably a Tarahumara dialect, or it may be more closely related to Guarijío and Chínipa. Guazapar, Jova, Pachera, and Juhine may possibly all be dialects of Tarahumara.
Guisca
Hio: possibly a Taracahitic language
Huite: closely related to Ocoroni, and may be Taracahitic
Jova : most often linked with Opata, although some scholars classify it as a Tarahumara dialect. Miller considers it to be "probably Taracahitan."
Jumano; also Humano, Jumana, Xumana, Chouman, Zumana, Zuma, Suma, and Yuma. Suma is probably the same language, while Jumano is possibly Uto-Aztecan.
Lagunero: may be the same as Irritila, and may also be closely related to Zacateco or Huichol.
Macoyahui: probably related to Cahita.
Mocorito: a Tahue language, which is Taracahitic.
Naarinuquia : Uto-Aztecan affiliation is likely, although it may instead be non-Uto-Aztecan language possibly related to Seri due to the speakers' maritime economy.
Nacosura: an Opata dialect
Nio: completely undocumented, although it is perhaps related to Ocoroni.
Ocoroni: most likely a Taracahitic language, and is reported to be mutually intelligible with Chínipa, and similar to Opata. Related languages may include Huite and Nio.
Oguera
Patarabuey: unknown affiliation, and is possibly a Nahuatl dialect.
Tahue: may also include Comanito, Mocorito, Tubar, and Zoe. It is possibly a Taracahitic language, and is definitely not Nahuan.
Tanpachoa: unknown affiliation, and was once spoken along the Río Grande.
Tecuexe: speakers were possibly part of a "Mexicano" colony.
Teco-Tecoxquin: an Aztecan language
Tecual: closely related to Huichol. According to Sauer, the "Xamaca, by another name called Hueitzolme , all... speak the Thequalme language, though they differ in vowels."
Témori: may be a Tarahumara dialect.
Tepahue: possibly a Taracahitic language. Closely related languages or dialects include Macoyahui, Conicari, and Baciroa.
Tepanec: an Aztecan language.
Teul : a Pimic language, possibly of the Tepecano subgroup.
Xixime : spoken by the Xiximes, possibly a Taracahitic language. Subdivisions are Hine and Hume. Its links with Acaxee are uncertain.
Zacateco: often considered the same as Acaxee, although this is uncertain. It is possibly related to Huichol, although Miller leaves it as unclassified.
Zoe: possibly a Taracahitic language, with Baimena as a subdivision. It is possibly affiliated with Comanito.
