The most ancient and precious fossils of the whole Sicily can be found here: they have been settling and stratifying since the Permian period and have given origin to calcareous rocks. They are foraminifers, sponges, bryozoans, brachiopods, ammonites, trilobites, and ostracods, all marine animals which lived in a stretch of the archaic ocean Tethys, the forerunner of the present-day Mediterranean, which was situated in the continental area of Pangaea before breaking up into the present continents.