Editing Nicolas Steno (section)

=== Paleontology ===
{{See also|History of paleontology}}
[[File:Steensen - Elementorum myologiae specimen, 1669 - 4715289.tif|thumb|upright|''Elementorum myologiae specimen'': Illustration from Steensen's 1667 paper comparing the teeth of a shark head with a fossil tooth.]]
In October 1666, two fishermen caught a huge female [[shark]] near the town of [[Livorno]], and [[Ferdinando II de' Medici]], Grand Duke of Tuscany, ordered its head to be sent to Steensen. Steensen [[dissection|dissected]] the head and published his findings in 1667. He noted that the [[Shark tooth|shark's teeth]] bore a striking resemblance to certain stony objects, found embedded within rock formations, that his learned contemporaries were calling ''glossopetrae'' or "tongue stones". Ancient authorities, such as the [[Ancient Rome|Roman]] author [[Pliny the Elder]], in his ''[[Natural History (Pliny)|Naturalis Historia]]'', had suggested that these stones fell from the sky or from the [[Moon]]. Others were of the opinion, also following ancient authors, that [[fossil]]s naturally grew in the rocks. Steensen's contemporary [[Athanasius Kircher]], for example, attributed fossils to a "lapidifying virtue diffused through the whole body of the geocosm", considered an inherent characteristic of the earth – an [[Aristotelianism|Aristotelian]] approach. [[Fabio Colonna]], however, had already shown by burning the material to show that ''glossopetrae'' were organic matter (limestone) rather than soil minerals,<ref>[https://web.archive.org/web/20070318025357/http://www.musei.unina.it/Paleontologia/3.2.3.htm Breve storia della paleontologia], internet site of Centro dei Musei di Scienze Naturali, university of Naples Retrieved 10 January 2012.</ref> in his treatise ''De glossopetris dissertatio'' published in 1616.{{sfnp|Abbona|2002|loc=Geologia |ps=: Colonna had been schooled in the collection of [[Ferrante Imperato]], apothecary and ''virtuoso'' of Naples, who published his natural history notes in 1599.}}<ref>{{cite journal|doi=10.1080/08912963.2013.825257|title='The vain speculation disillusioned by the sense': The Italian painter Agostino Scilla (1629–1700) called 'The Discoloured', and the correct interpretation of fossils as 'lithified organisms' that once lived in the sea|journal=Historical Biology|volume=26|issue=5|pages=631–651|year=2014|last1=Romano|first1=Marco|bibcode=2014HBio...26..631R |s2cid=129381561}}</ref> Steensen added to Colonna's theory a discussion on the differences in composition between glossopetrae and living sharks' teeth, arguing that the chemical composition of fossils could be altered without changing their form, using the contemporary [[Corpuscularianism|corpuscular theory of matter]].

Steensen's work on shark teeth led him to the question of how any solid object could come to be found inside another solid object, such as a rock or a layer of rock. The "solid bodies within solids" that attracted Steensen's interest included not only fossils, as we would define them today, but minerals, crystals, encrustations, veins, and even entire rock layers or [[stratum|strata]]. He published his geologic studies in ''De solido intra solidum naturaliter contento dissertationis prodromus'', or ''Preliminary discourse to a dissertation on a solid body naturally contained within a solid'' in 1669. This book was his last scientific work of note.{{sfnp|Garrett Winter|1916|p=182}}{{efn|[[Leibnitz]] came to know and esteem Steensen in Hannover and expressed deep regrets that he had abandoned his earlier studies.{{sfnp|Garrett Winter|1916|p=182.}} }} Steensen was not the first to identify fossils as being from living organisms; his contemporary [[Robert Hooke]] also argued that fossils were the remains of once-living organisms.<ref>{{cite book|last=Rudwick|first=Martin J.S.|author-link=Martin J. S. Rudwick|title=The Meaning of Fossils|year=1976|publisher=The University of Chicago Press|page=54}}</ref>