Hammond's oryzomys is a rarely recorded rodent of the Chocó forests on the western Andean slope of northern Ecuador.
A new account examined the external form of one adult male, including its ears, nose, and front and hind feet. The sample is too small to describe variation across the species.
Researchers say several features of that male suggest life in trees. This is an interpretation from anatomy, not a direct observation of the animal moving in trees.
An extinction-risk assessment has not been added yet.