T. g. bonafidei (Moojen, 1948) T. g. gratiosus (Moojen, 1948) Trinomys gratiosus is a species in the mainly South American family Echimyidae, the spiny rats; it occurs in southeast Brazil from the south bank of the River Doce, Espirito Sante, southward to Teresopolis, Rio de Janeiro.

Some evidence suggests that the lineage of the South American spiny rats is older than might have been expected and in spite of morphological resemblance, the populations have diverged widely.

[3] In 2008 the IUCN Red List rated Trinomys gratiosus as Least Concern (LC); its population is apparently large, it does not seem to be declining fast enough for listing in a threatened category, and the habitat is not under obvious threat.

[1] The species does not occur and is not widely known in Anglophone regions, so the idea of popular English names raises problems.

[5] No authority to date has proposed a better option than using the species name, Trinomys gratiosus in English.