ClipArt ETC
"Columba livia. Sacrum of a nestling (about fourteen days old), ventral aspect. c1, centrum of first sacral vertebra; c1, centrum of fifth caudal; c. r, first sacral rib; l1, centrum of first lumbar; l3, of third lumbar; s1, of fourth lumbar; s3, of sixth lumbar; tr. p, transverse process of first lumbar; tr. p', of fifth lumbar; tr. p'', of first sacral." -Parker, 1900

Rock Pigeon Sacrum

"Columba livia. Sacrum of a nestling (about fourteen days old), ventral aspect. c1, centrum of first…