[4] The squarenose unicornfish has a specific name which honours Michael McDade, a spearfisher and the records officer for the Australian Underwater Federation.

McDade collected and donated many specimens of rare fishes to the Queensland Museum, one of which was the type of this species.

Its body has a standard length which is about 2.4 to 3 times its depth with a rounded dorsal profile.

The caudal peduncle has a pair of bony plates on each side, each bearing a forward pointing spine.

It occurs along the east African coast from Mozambique to KwaZulu Natal, around Madagascar, Mauritius, the Chagos Archipelago, the Maldives, east through Indonesia into the Western Pacific north to Taiwan and south to Australia.