[2] The genus' scientific name references the type locality: it is derived from Ancient Greek tympanon (drum) + nesiotes (islander).

The thin-walled bone has a second toe trochlea that attaches notably kneewards from the others and is angled slightly outwards while the hallux was vestigial or missing, as is typical for the pseudotooth birds.

The type genus of that supposed suborder, the enigmatic Late Oligocene Cladornis from the Argentinian part of Patagonia, like the present species is only known from a distal right tarsometatarsus end.

But Cladornis is more generally held to be a terrestrial bird of unclear affiliations rather than a seabird nowadays, and the Cladornithes are not used anymore by recent authors.

[7] As regards the supposed Cyphornithidae, most if not all pseudotooth birds placed there are probably closely related to the better-known Pelagornis, type genus of the family Pelagornithidae.