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.
They form the region of the spinal column inferior to the cervical vertebrae of the neck and superior to the lumbar vertebrae of the lower back.... Click to read more below. The thoracic vertebrae are a group of twelve small bones that form the vertebral spine in the upper trunk.Thoracic vertebrae are unique among the bones of the spine in that they are the only vertebrae that support ribs and have overlapping spinous processes.he thoracic vertebrae are a group of twelve small bones that form the vertebral spine in the upper trunk. Thoracic vertebrae are unique among the bones of the spine in that they are the only vertebrae that support ribs and have overlapping spinous processes.