urosteon

‖n.; pl. L. Urostea E. Urosteons [ NL., fr. Gr. &unr_; the tail + &unr_; a bone. ] (Anat.) A median ossification back of the lophosteon in the sternum of some birds. [ 1913 Webster ]

‖n.; pl. L. Pleurostea E. -ons [ NL., fr. Gr. &unr_; a rib + &unr_; a bone. ] (Anat.) The antero-lateral piece which articulates the sternum of birds. [ 1913 Webster ]