It is only thanks to the good eye of a paleontologist who happened to walk by the altar, Andrea Tintori, that the piece of marble supporting the columns has risen to better fame. Its surface (see right) clearly shows a section of the skull of a dinosaur of as-of-yet unknown species, and yet apparently nobody had noticed it before.
A second section of the same skull is present in another slab of marble beyond the altar. The main section clearly shows the skull, nasal cavities, and several teeth. It is not yet clear what animal it belonged; future studies will probably allow to understand it.
The marble with which the altar is built comes from the Monte San Giorgio mine in Arzo, Switzerland, which is famous for the fossilized remains contained in its rock, a pinkish calcareous mineral containing iron oxides, which was formed 180 million years ago. Now paleontologists have received authorization and funding to study the material in more detail: the slabs will be replaced with others, and a three-dimensional reconstruction of the bone will be possible.