What is fused to form the coxal bone?

The coxal, or hip bone consists of the pubis, the ilium, and the ischium, as reported by Teach Me Anatomy. Those three bones are distinct and separate at birth but fuse together as people enter young adulthood.

The ilium, the ischium, and the pubis fuse together in the pelvis to form the acetabulum, as stated by Teach Me Anatomy. The ilium is situated at the top of the coxal bone, while the stronger ischium is located at the bottom. The pubis is stationed at the front of the hip bone, and it serves as the internal scaffold for the reproductive organs. In babies, these three bones are separated by a layer of triradiate cartilage, which disappears as the bones fuse.