Nautiloidea - Fossilised animal - cleoniceras in sezione - 17 cm - 14 cm

Extremely important group from a fossil perspective belonging to the Devonian-Cretaceous period. Fully extinct at the end of the Cretaceous, it is believed to derive from ancestors belonging to Nautiloidea. Although part of the molluscan cephalopod group, CLEONICERAS is distinguished above all by the shape of the shell characterized by bilateral symmetry. The shell is divided into a single anterior region where the animal resided and a posterior region subdivided into chambers. The line of closure between the chambers is very indicative and facilitates species recognition. Moreover, its outline, in the early forms rather simple and linear, progressively changed up to the more recent ammonites where it is often very jagged and almost baroque. The sizes are variable: it starts from a few centimeters but can reach up to 10 cm. Since this is a completely extinct marine species, it is possible only to hypothesize their lifestyle. It is believed that forms with smooth exteriors shells were swimmers, often predators. Species with more ribbed and ornamented shells were predominantly benthic. Unmissable lot: Beautiful specimen of Cleoniceras cut open to reveal the extraordinary internal structure, made possible by fossilization through aragonite. This natural process causes the original organic tissues to be gradually replaced by aragonite, a mineral that fills the shell cavities and transforms them into a sparkling composition of crystals, exceptionally preserving internal details and turning the fossil into a true work of nature’s art. Observing the outside of this beautiful fossil, the characteristic sutural lines of the species are clearly visible, intertwining in a pattern that recalls the sinuous movements of flames. A true natural masterpiece. Stand not included, obtained from recycled materials used and used for photography purposes only.

估價:$419

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