The Rio de Janeiro arboreal rat has a rusty back and a long tail. Records are scarce, and its detailed natural history is still poorly known.
Its back is rusty, the sides are paler, and the underside is yellowish-white. The account also describes a long tail.
The plan describes it as arboreal. It also says records are sparse and that details such as its diet remain unknown.
An extinction-risk assessment has not been added yet.