 George Shaw described the species as "Didelphis obesula" in 1797.While some authorities list as many as five subspecies ("I. o. fusciventer", "I. o. obesulus", "I. o. peninsulae", "I. o. affinus", "I. o. nauticus"), the most recent edition of "Mammal Species of the World" only lists "I. o. nauticus" as a valid subspecies, aside from the nominate; the others are given synonym status.Southern brown bandicoots have a stocky body with a short snout and short, rounded ears.