The phylum Chordata is a taxonomic group. All animals which have a  spine, or backbone, are classified in the phylum Chordata. There  are three subphylums in Chordata: Uroch â¦ ordata (tunicates),  Cephalachordata (lancelets), and Vertebrata (vertebrates).
The 12 vertebrae in the upper back make up what is known as the thoracic spine. They curve outward and inward to provide structure for the rib cage. The bones provide structure and flexibility for the body, while protecting the spinal colu... Read More.
The Ribs. 12 pairs, connected to the 12 thoracic vertebrae in the back. The upper 7 pairs of ribs (true ribs or vertebrocostal ribs) are attached to the sternum directly with costal cartilages. Ribs 8, 9, and 10 (vertebrochondral ribs) are attached indirectly to the sternum through the cartilage of rib 7.