Nautiloidea - Fossilised animal - cleoniceras in sezione - 13.6 cm - 11 cm

Very important fossil group belonging to the Devonian-Cretaceous period. Totally extinct by the end of the Cretaceous, it is thought to derive from ancestors belonging to the Nautiloidea. Although belonging to the cephalopod molluscs, CLEONICERAS is distinguished above all by the shape of the shell, characterized by bilateral symmetry. The shell is divided into an undivided anterior region where the animal resided and a posterior region divided into chambers. The line of closure between the chambers is very indicative and facilitates the recognition of the species. Moreover, its outline, in the earlier forms rather simple and linear, has gradually evolved to the more recent ammonites where it is often very jagged and almost baroque. Sizes vary: starting from a few cm but can reach up to 10 cm. Since these are entirely extinct marine species, we can only hypothesize their lifestyle. It is believed that forms with smooth shells externally were swimmers, often predators. Species with more ribbed and ornamented shells were predominantly benthic. Lotto imperdibile: Bell’esemplare di Cleoniceras sezionata per rivelare la straordinaria struttura interna, resa possibile dal processo di fossilizzazione tramite calcite. Observing the external part of this beautiful fossil, the sutural lines characteristic of the species are clearly visible, intertwining in a pattern that recalls the sinuous movements of flames. A true natural masterpiece. Piedistallo non incluso, ottenuto da materiali di recupero utilizzato ed utilizzato a soli fini fotografici.

Stima:€180

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