The southern big-eared mouse is a sturdy rodent of southern South America. It lives in grasslands and forests and feeds mainly on plants.
It is heavy-bodied, with thick dull fur, relatively large ears, and strong feet. The back is gray or brown and grizzled, while the belly is paler.
It occurs in humid grasslands and meadows, shrubby steppe, and Nothofagus forest, and is primarily herbivorous.
An extinction-risk assessment has not been added yet.