This genus is founded on cranial characters: Basipterygoid processes of
parasphenoid present but rudimentary. The vomer broad, flat, and
three-pointed in front. Maxillaries anchylosed to the premaxillaries, the
latter anchylosed to the expanded ossified base of the nasal septum. The
ossified mesethmoid stretches backward and is lodged in the concavity of
the upper surface of the vomer, so that it presents a form intermediate
between the complete aegithognathous forms, such as _Corvus_, and the
compound aegithognathous forms, such as _Gymnorhina_, in which
desmognathism was superadded by "anchylosis of the inner edge of the
maxillaries with a highly ossified alinasal wall and nasal septum"
(Parker).