Caudal vertebrae more than thirteen, without a pygostyle, but with about twelve pairs of rectrices.
In the Ratitae and Tinamidae a pygostyle is rarely or imperfectly developed.
The tail is comparatively long, and formed of twelve vertebrae with only slight indications of a pygostyle.
Rump′-post, the share bone or pygostyle of a bird; Rump′-steak, steak cut from the thigh near the rump.
The origin of pars caudifemoralis in three legs is directly from the anteroventral surface of the pygostyle.
In proportionate size (see Table 7), the pygostyle of Bombycilla is the smallest in the family.
The posterior caudal vertebrae are ankylosed forming a pygostyle.
The posterior caudal vertebrae are not united together to form a pygostyle.
They all agree in having a short tail whose component vertebrae are commonly ankylosed together forming a pygostyle.
The tail is short and the posterior caudal vertebrae are generally ankylosed together forming a pygostyle.