Final answer:
The pelvic girdle is made up of two coxal bones, the sacrum, and the coccyx, and is supported by ligaments that stabilize the pelvic girdle, sacrum, and lumbar vertebrae.
Step-by-step explanation:
The structure in question consists of the pelvic girdle, which is composed of two coxal bones (also known as hip bones), the sacrum, and the coccyx. These bones are interconnected and stabilized by robust ligaments. The pelvic girdle serves as the site of attachment for the lower limbs and is crucial for weight bearing and locomotion. The hip bones are formed by the fusion of three bones: the ilium, the ischium, and the pubis. The sacrum is a triangular-shaped bone that forms from the fusion of five sacral vertebrae and supports the weight of the body. Finally, the coccyx or tailbone is derived from the fusion of four small coccygeal vertebrae.