Guildingia obtecta Iredale & Hull 1932; Morton & Miller 1968, 1973; Walsby & Morton 1982 Plaxiphora obtecta is a large chiton in the family Mopaliidae,[2] endemic to New Zealand, where it is most often found on the West Coast of the North Island.

It is called Haka-hiwihiwi by some Māori[3] and was likely a food source.

Up to 90 millimetres (3.5 in) long and 65 millimetres (2.6 in) wide, making it one of the largest chitons found in New Zealand.

It has a broad dark brown girdle dotted with small short bristles, and reduced dark green valves, sometimes with a paler stripe down the centre.

It is frequent around the holdfasts of algae and in rock crevices around the low intertidal zone, usually on exposed coasts.