Complex sentence: Originally described as "Isothrix rufodorsalis" in 1899, then placed in the genus "Diplomys" in 1935, the subfamily Echimyinae (including this species) was comprehensively reviewed in 2005 where it is now placed in the monotypic genus "Santamartamys".
Split into simpler sentences: Originally described as "Isothrix rufodorsalis" in 1899, it was placed in the genus "Diplomys" in 1935. The subfamily Echimyinae (including this species) was reviewed in 2005, and as a result it is now placed in the monotypic genus "Santamartamys".