The Atlas. This is the topmost vertebra, and with the axis, it forms a joint that connects the skull to the spine. These two parts of the body (The Atlas and The Axis) are special, and different from normal vertebra, because they are made to allow a greater range of motion and movement in the head. I hope this helps! Also, google is always a helpful tool to use as well. :)
In general, Yes True <span />
It produces new, organic, rich soil, that can contribute to agriculture and farming, as well as the decomposers that live in them. It is very good to compost.