ABSTRACT
It is well known that fossils of shark’s teeth were named as ‘tongue stones’ (glossopetrae in Latin) because of their similarity in shape to the tongues of animals. However, Nicolaus Steno (1638–1686) decidedly revised this kind of explanation in the latter half of the seventeenth century. He recognized them as shark’s teeth in his treatise of 1667, adopting the figures of a shark head with teeth in its mouth and fossil ‘tongue stones’ borrowed from the then unpublished manuscript on the Vatican mineral collection by Michele Mercati of San Miniato (1541–1593). This article reconsiders the role of the palaeontological illustrations in this process because Mercati himself had recognized the similarity of the shapes of the shark teeth and glossopetrae but he could not neglect the difference of material between them. Although Steno’s skill as a comparative anatomist convinced him of the organic origin of the fossils, there were still problems of sedimentation to solve. We will first review the opinions of early modern naturalists concerning fossil objects and then focus on how Steno solved the problem to pave the way for his epoch-making dissertation Prodromus (1669). At the same time, we will pay attention to how the set of figures would continue to be borrowed by such authors as Paolo Silvio Boccone (1674), Michael Bernhard Valentini (1704), and Gottfried Wilhelm Leibniz (1749, originally circa 1691). In the meantime, the original manuscript with figures was published in 1717 as Metallotheca Vaticana by Giovanni Maria Lancisi, the Italian anatomist and one of Steno’s acquaintances. Lancisi made annotations to this text that suggested the fossil controversy was evolving, citing the names of Cesalpino, Steno, Boccone, and Vallisneri. Thus, we can understand how the illustrations with its hidden text functioned well in the fossil controversy by the strategic usage by Steno of the Vatican collection, a sort of ‘museum on paper’.
