Monodonta, no jaws, spire not prominent, no umbilicus, columella toothed.
The elongated cylindrical cones grow chiefly at the ends of the upper branches; they are purplish at first, but become afterwards green, and eventually light brown; their scales are slightly toothed at the extremity; they ripen in the autumn, but seldom discharge their seeds until the following spring.
In 1880 Marsh brought out Odontornithes, a monograph of the extinct toothed birds of North America.
Fiirbringer supposes that birds must have begun with toothed forms of small or moderate size, with long tails and four lizard-like feet and bodies clothed with a primitive kind of down.
In the male, moreover, the pincers are caliper-like and toothed at the base, whereas in the female they are untoothed and only lightly curved at the tip. These differences suggest that the pincers aid in the pairing of the sexes.