What does Five nonrib-bearing lumbar-type vertebrae?

Five nonrib-bearing lumbar-type vertebrae: this is a characteristic feature of the mammalian vertebral column. In mammals, the vertebral column is divided into five regions: cervical (neck), thoracic (chest), lumbar (lower back), sacral (pelvic), and caudal (tail). The lumbar region is characterized by the presence of five vertebrae that do not bear ribs. This is in contrast to the thoracic region, where each vertebra bears a pair of ribs. The lumbar vertebrae are responsible for providing support and flexibility to the lower back. They also play an important role in protecting the spinal cord and other structures in the lower back.