O'Connell's spiny-rat has a reddish-orange, coarse coat on its back and a white underside. A field guide from Colombia's seasonally flooded savannas reports solitary records there.
A South American reference describes a reddish-orange back interspersed with black hairs, a white underside, and a bicolored tail; the spines are weakly developed.
The Colombian field guide describes it as solitary and terrestrial, with records in trees or burrows and feeding on fruits and seeds.
An extinction-risk assessment has not been added yet.