This spiny rat is recorded in forests of southeastern Brazil. Its upperparts are ochraceous-buff, its underside white, and a darker stripe runs along the middle of the back. The type and paratype specimens were collected in mature forest in Espírito Santo.
The upperparts are described as ochraceous-buff, the ventrum as white, and the mid-dorsum as darker. The tail is brown above and white below.
The type and four paratypes of the nominate subspecies T. g. gratiosus were collected in mature forest at Floresta da Caixa d’Água, Santa Teresa, Espírito Santo, Brazil.
An extinction-risk assessment has not been added yet.