The Fly River Grassbird occurs in the Fly River lowlands of southeastern New Guinea. The account uses Poodytes albolimbatus as its heading and also lists Megalurus albolimbatus.
It has a reddish-cinnamon crown and black streaks on the back. White edges on the wing feathers form a white panel when the wing is closed.
It inhabits lowland swamps and usually stays hidden low in reeds near the waterline. It is often seen only when flushed by a boat; the account says its diet is not well known.
An extinction-risk assessment has not been added yet.