The only species in the genus is Polyplacapros tyleri, Tyler's boxfish, which is found in the southwestern Pacific Ocean.

[3] The 5th edition of Fishes of the World classifies this taxon in the family Aracanidae which is in the suborder Ostracioidea within the order Tetraodontiformes.

This refers to the carapace, made up of bony plates on the body, and the pig-like head of this fish.

There is another cleft extending from the origin of the dorsal fin to the spine on the ridge along the side and another from the lower end of the gill slit to the mouth.

[6] Polyplacapros is found in the southwestern Pacific Oceans at depsth between 30 and 160 m (98 and 525 ft) and has been recorded from seamounts in the Tasman Sea, the Norfolk Ridge, Lord Howe Rise and northern New Zealand.