Thrichomys inermis is endemic to the Caatinga (contra Carmignotto et al. 2012, Paglia et al. 2012), and has been recorded in the Brazilian state of Bahia (Pereira and Geise 2009, Pessôa et al. 2015a). Alleged records of the species for the Brazilian state of Tocantins, from what seems to correspond to the Cerrado biome, reported in abstracts of meeting presentations have permeated through the literature – e.g., cited by Oliveira and Bonvicino (2006), Bonvicino et al. (2008), Pessôa et al. (2015a) – but, to the best of our knowledge, tangible evidence of the species being present in states and biomes other than Bahia and the Caatinga, respectively, is still lacking. The aforementioned abstracts are as follows:

Carvalho AH, Fagundes V (2005) Área de ocorrência de três táxons do gênero Thrichomys (Echimyidae, Rodentia) baseados em identificação cariotípica. In: Fagundes V, Costa LP, Leite YLR, Mendes SL (Eds), Livros de resumos, III Congresso Brasileiro de Mastozoologia. Espírito Santo, Aracruz, p. 102.

Carvalho AH, Lopes MOG, Svartman M (2008) Cariótipo de Thrichomys inermis (Rodentia, Echimyidae) do Tocantins. XXVII Congresso Brasileiro de Zoologia, Curitiba.

The red list of the IUCN ver. 3.1 assigned the category “Least Concern” to Thrichomys inermis (see Bonvicino and Geise 2008b). The species was not included in the official list of threatened species of Brazil (ICMBIO-MMA 2016).