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 thoracic vertebrae are located in the middle section of the vertebral column, specifically inferior to the cervical vertebrae and superior to the lumbar vertebrae. These vertebrae span the large majority of the chest cavity area.here are 12 thoracic vertebrae (denoted as T1-T12) found in adult humans, and they are situated in between the cervical and lumbar vertebrae, with a general sizing larger than the cervical but smaller than the lumbar vertebrae.