The Guaira Spiny-rat has stiff spines mixed among the fur on its back. In a Venezuelan study, males and females differed in home-range overlap, and juveniles appeared at the start of the rainy season.
Stiff spines about23mm long are mixed into the back fur. The back is pale rufous with dark spine tips, and the chest and belly are white.
At a 9-ha Venezuelan study site with 225 trap stations, adult females' home ranges did not overlap, while males' did. Juveniles appeared at the start of the rainy season and were absent in the dry season.
The tail is hairy, black above and white below.
The upper surfaces of the hands and feet are white, with a slightly browner outer edge.
An extinction-risk assessment has not been added yet.