The scientific name refers to New Zealand. Changes to skink nomenclature mean there is potential confusion surrounding the name O. zelandicum. Before 1977 the brown skink was known by the name Leiolopisma ornata, and the combination Leiolopisma zelandica was also applied to the species now known as O. polychroma (Hardy 1977, Patterson & Daugherty 1990).
Similar to common skink, O. polychroma, but most individuals readily distinguished by having pale vertical denticulate markings beneath the eye (versus absent, or with a pale longitudinal mark), or in some cases the broad dark stripe on the side lacks the pale stripe from its lower border (versus always present, albeit sometimes fragmented). Some small specimens similar to copper skink, O. aeneum but lower eyelid transparent (versus opaque).
A medium sized, slender skink (SVL up to 73mm, total length up to 145mm, Jewell 2008). Head short, compact. Snout pointed. Dorsal surfaces light to dark brown with occasional indefinite dark brown mid-dorsal stripe. Some shoreline populations are black. Denticulate markings on jaws. Lateral surfaces darker brown, often flecked. Dorso-lateral stripe may be present to tail, often as a thin cream stripe above a broad dark brown lateral stripe. Another broken cream stripe may also be present below this lateral stripe. Ventral surfaces grey, straw-coloured or suffused with red or orange; sometimes spotted with black. Throat grey, usually spotted with black. Soles dark brown or black. Sides and underparts of tail and hindlimbs sometimes reddish (Jewell 2008).