A computer model of Dinornis robustus (pink) next to the much smaller but more skeletally robust P. australis.
Credit: C.A. Brassey, R.N. Holdaway, A.G. Packham, J. Anne, P.L. Manning, W.I. Sellers and PLOS ONE. http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0082668
Source: http://www.livescience.com/42076-giant-moa-loses-weight.html

The crested moa, Pachyornis australis, is a species of moa from the family Dinornithidae. It is one of the 11 known species of moa to have existed. Moas are grouped together with emus, ostriches, kiwis, cassowaries, rheas, and tinamous in the clade Palaeognathae. Some of the species of this group are flightless and lacks a keel on their sternum. The name crested moa is due to pits being found in their skulls, suggesting they had crests. These cranial pits are also found occasionally in Dinornis, Anomalopteryx, and other Pachyornis species. Pachyornis australis weighed around 75 kg. The crested moa was smaller than the heavy-footed moa (Pachyornis elephantopus) and their bones are sometimes mistaken for those of P. elephantopus due to their similar structure. Order: Dinornithiformes, Family: Anomalopteryginae.
Synonyms:
Pachyornis elephantopus Cracraft 1976 non (Owen 1856) Lydekker 1891
Mesopteryx sp. β Parker 1895