The skull is broad and much depressed, with a comparatively wide, somewhat
pointed and deflected beak. Breadth at the squamosals twice the height at
basi-temporal. It has a flattened frontal region, and a wide median ridge
on the upper surface of the praemaxillae. The mandible is in the form of a
narrow U, with the angle much inflected, no distinct anticular process, and
the symphysis moderately wide, narrowing anteriorly, with a prominent and
broad inferior ridge, widest in front. The quadrate is elongated, with a
very large pneumatic foramen. The sternum is nearly as long as broad, very
convex, with distinct coracoidal facets, 3 costal articulations, very small
and reflected costal processes, the lateral processes very broad and widely
divergent, and a wide xiphisternal notch. The pelvis is narrow with a high
ilium, in which the inferior border of the postacetabular portion is flat,
and does not descend as a sharp ridge below the level of the anterior
postacetabular vertebrae. The pubis has a small pectineal process; and the
ventral aspect of the true and postacetabular vertebrae is very broad and
much flattened.
The distal extremity of the tibio-tarsus is not inflected. A hallux is
present in some species. The tibio-tarsus and tarso-metatarsus are long and
slender, the length of the latter equalling and more often exceeding the
length of the femur, and also exceeding half the length of the
tibio-tarsus. The femur is comparatively long and slender, with a short
neck, the head rising but slightly and projecting only a small distance,
the linear aspera in the form of a long irregular line, the outer side of
the distal extremity moderately expanded, the popliteal depression small,
deep, and sharply defined, the profile of the inner condyle semi-ovoid and
narrow, and the interior trochlear surface nearly flat. The phalangeals of
the pes are long and comparatively slender, the proximal surface of the
terminal segments not being trefoil-shaped. In the vertebral column the
middle cervicals are long and narrow, with the postzygapophyses directed
much outwardly and separated by a very deep channel, and the posterior face
of the centrum low and wide. The dorsals have short transverse processes
and neural spine, the anterior and middle ones (those with a haemal spine
or carina) having a large anterior pneumatic foramen between the nib-facet,
the foramen being triangular in shape. All the species of this genus are of
comparatively large size, and include the tallest members of the family.
Type of the genus: _Dinornis novaezealandiae_ (Owen).