Perisphinctes geron Zittel3D ModelNoAI
Group: ammonite
Age: Late Jurassic
Location: Leysin, Switzerland
Specimen size: 9 x 8 cm
Inventory Number: 1688
Description: Due to their wide palaeogeographic distribution, the numerous morphological characters that allow species to be distinguished and the rapid evolution of species, ammonites (subclass Ammonoidea, an extinct group of cephalopods) occupy a special place in palaeontology and stratigraphy. Although at first sight they resemble the Nautilus, a nautilid still living today, ammonites are more closely related to octopuses, squids and cuttlefish. The genus Perisphinctes is recognised by its involute to slightly convolute, medium-sized aragonite shell (phragmocone) with strong radial ribs that split near the outer edge. The first ammonites appeared during the Devonian (419-359 million years ago) and the last ammonites died out at the end of the Cretaceous, about 66 million years ago.
Photo: Ajda Lovše. Model: Marko Vrabec. Description: Luka Gale.
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