The most extraordinary feature is unquestionably the former existence of the gigantic Dinornithes or moas and, another family of Ratitae, the weird-looking kiwis or Apteryges, which are totally unlike any other existing birds.
At any rate we begin to see that some of the Ratitae, namely the Rheidae, may possibly be an early and then much modified offshoot of such of the Carinatae as are now represented by the Crypturi, whilst in another part of the world, and at a much later time, kiwis and moas have sprung from a somewhat more Gallilorm stock, which points to a descent from a still undivided GalliformTinamiform mass.
The feathers have a large after-shaft which is of the size of the other half, likewise in agreement with the Australian Ratitae, while in the others, including the kiwis, the after-shaft is absent.
Another important point, in which the moas agree with the other Ratitae and differ from the kiwis, are the branched, instead of simple, porous canals in the eggshell.
The relationship with Aepyornis of Madagascar is still problematic. Whilst the moas seem to have been entirely herbivorous, feeding not unlikely upon the shoots of ferns, the kiwis have become highly specialized wormeaters.