Rib
Ribs are classed as flat bones which usually have a protective role in the body. Humans have 24 ribs, in 12 pairs. All are attached at the back to the thoracic vertebrae, and are numbered from 1–12 according to the vertebrae they attach to. The first rib is attached to thoracic vertebra 1 (T1). At the front of the body most of the ribs are joined by costal cartilages to the sternum. The ribs connect to the vertebrae with two joints, the costovertebral joints.
Ashva
In RV 1.162.18, the sacrificial horse is described as having 34 (2x17) ribs:
Frawley (2005) speculates that the Rigvedic horse could therefore be the Indian "Equus sivalensis" (which may or may not have had 34 ribs; modern horses usually have 36, with occasional specimens of 34 or 38).