The sutures in the skull.
We are born with 300 bones in our bodies but, as adults, we have 206. In the skull, our cranial bones fuse together. In the image below, you can see where the some of the bones have fused together.
This fusion is a little different than fusion elsewhere, as the bones are held together by Sharpey’s fibers, which allow for more movement. The skull fuses more as we age.
The frontals were 2 and fuse to 1 in adults. The occipital bone, the two parietal bones, and two temporal bones fuse to make up the cranium. Also in the skull, the maxillae were 2 bones but fuse together.
The sacrum is fused from five pieces. The coccyx is usually 4-5 fused pieces.
The sternum is fused from 3 bones: manubrium, body and xiphoid process.
The os coxa has 3 fused bones: illium, ischium, pubis in each side.
There are 12 pairs of ribs in both males and females; top 7 pairs are true and are directly attached to the sternum with costal cartilage,, numbers 8-12 are false and join to the 7th rib and not the sternum, and numbers 11-12 are floating.