Another possibly extinct Tacanan language is Mabenaro; Arasa has been classified as Tacanan, but appears to have more in common with Panoan.

Jolkesky (2016) notes that there are lexical similarities with the Kayuvava, Tupi, and Arawak language families due to contact.

[1] Below is a full list of Tacanan language varieties listed by Loukotka (1968), including names of unattested varieties.

[2] Loukotka (1968) lists the following basic vocabulary items for the Tacanan languages.

Sample vocabulary of four Tacanan languages, along with Proto-Panoan for comparison, from Nikulin (2019):[3] Tacanan languages, in particular Cavineña and Ese Ejja, have among the richest associated motion systems in the world's languages.