Skull with a short and wide beak. Pectoral girdle very small or absent,
wing absent, only an indication in _Dinornis dromioides_. Hallux absent or
present. An extension bridge to the tibio-tarsus, which is placed near the
inner border of the bone. No superior notch to the sternum. Most of the
species of very large size. The tarso-metatarsus is either long and slender
or short and wide, and its anterior surface may or may not be grooved. The
second trochlea is longer than the fourth, the third is not pedunculated,
and there is no perforation in the groove between the third and fourth
trochlea. In the tibio-tarsus the cnemial crest rises well above the head;
the extensor groove is separated by a considerable interval from the inner
border of the bone. There is a well-defined intercondylar tubercle; the
intercondylar gorge is deep, and there is no deep pit on the lateral
surface of the entocondyle. The femur may be either slender or stout, but
is not markedly curved forwards. The popliteal depression is deep, and the
summit of the great trochanter rises considerably above the level of the
head. The pelvis approximates to that of the _Apterygidae_, but the
pectineal process of the pubis is less developed, and the ischium and pubis
may be longer and more slender. The coracoid and scapula are aborted and
may be absent. The sternum, which may be either long and narrow, or broad
and short, differs from that of the _Apterygidae_ by the absence of the
superior notch, the divergent lateral processes, and the reduction of the
coracoidal grooves to small facets or their total disappearance. The
cervical vertebrae are relatively short, an expanded neural platform as far
as the sixth.
In _Anomalopteryx_ and _Megalapteryx_ the number of cervical vertebrae is
21, and there are 2 cervico-dorsal and 4 free dorsal vertebrae, so it is
fair to assume that this is the correct number throughout the family.
The feathers had after-shafts.