Compare fetal sternum and adult sternum?

The ossific centers appear in the intervals between the articular depressions for the coastal cartilages, in the following order: in the manubrium and first piece of the body, during the sixth month;...

Fetus=33 Adult=24 The 5 sacral and 4 coccyx bones of the fetus fuse together - that's why adults only have 24

I guess one could think of the sternum as the "backbone" that holds the ribs together, keeps them in place. The sternum and ribs are a cage like system that protects your heart and lungs from injury....

A fetus has 33 vertebrae. The bones of the sacrum and coccyx fuse together, so adults only have 24 vertebrae.

One is smaller. There are also more bones in the fetal skeleton because some bones fuse together by the time adulthood is reached.