Backache?

When we acquired this object we were told it was the vertebra of a hippo. It was left by previous occupants of a house we moved into in Nairobi in 1972. We have always taken it with us when we move as it is a good talking point. It is beginning to deteriorate having been outside all those years. I don't know if it is definitely from a hippo. At about 9 inches across it is certainly large enough.
So hot today we have had a lazy day indoors. Now it is a beautiful warm evening, just like mid summer.