pygostyle (pigostil)

[ Pygostyle.- Eight caudal vertebræ of an eagle ( Haliaëtus leucocephalus), of which the last, p, is the pygostyle. (Two thirds natural size.) style, upon which feathers are bunched in several pairs, it follows that, theoretically, a pygostyle includes or rep resents coalesced caudal vertebræ as pairs of feathers in the tailamely vers i theremse birds, up to twelve or more in some. But this view does not rest upon observation. Whatever its morphological character, the pygostyle is always the last bone of the tail, and always conspicuous in size; in shape it is very variable in different birds.