The armoured flathead was first formally described in 1907 By the Australian ichthyologist Allan Riverstone McCulloch with the type locality given as "35 miles east of Port Jackson, New South Wales, Australia, depth 800 fathoms".

[2] The specific name honours Scots-born Australian zoologist William Aitcheson Haswell, who led the expedition on which the type specimen was obtained.

[3][4] The armoured flathead has a highly flattened, broad head and an elongated depressed body.

There is a row of spiny, bony plates called scutes running along the flanks from the head to the caudal peduncle.

[7] Armoured flatheads are not targeted by commercial fisheries, despite being reputed to have highly palatable flesh, because the amount of edible muscle is too small even in the larger specimens.