Marmosa parda is an opossum known from a few localities in the cloud-forested eastern Andes of central Peru. Specimens examined in the 2020 revision had dull brownish-gray backs and mostly gray-based belly fur.
In the specimens examined, the back is dull brownish gray. Most belly hairs are gray at the base, while the chin and groin have yellowish or buffy fur. The exposed part of the tail is uniformly dark.
The species is known from a few localities in cloud forest on the eastern Andean slopes of central Peru.
An extinction-risk assessment has not been added yet.