Nautilus are still around, swimming deep in the Indian and Pacific oceans. They are relatives of octopus and of the ammonites they are found alongside at this site in Majunga, Madagascar. They have up to ninety tentacles, and propel themselves along with a sort of jet propulsion. They have changed very little since their Jurassic ancestors. Cymatoceras sakalavus are around 110 million years old.
These fossils have been polished and the suture pattern formed by their chamber walls adds a brilliant finish to the pleasingly tactile shape.