Maoritomella densecostulata is a species of sea snail, a marine gastropod mollusk in the family Borsoniidae, first described by R.N. Kilburn in 1986.
The height of the shell attains 4.6 mm, its width 2 mm. It is light orange-yellow to brownish orange, maintained from its Protoconch stage.
It exhibits a fusiform-biconical shape, typical of the genus, with pronounced axial ribs and spiral lirae that create a cancellate (latticed) sculpture. Their protoconchs are 0.65-0.68 mm wide and 0.53-0.58 mm tall.
This marine species occurs on the continental slope of Eastern Transkei, South Africa, as well as off the coast of Mozambique. They live 74-200 m from the coast.