Jurassic Ammonite Fossil Pendant 185 Million Years Old – Sterling Silver 925 - Height: 34 mm - Width: 18 mm- 6 g - (1)

The Charm of the Ancient Matter: a Sterling Silver 925 pendant made with an authentic fossil ammonite of the species Amaltheus margaritatus (de Montfort, 1808), originating from France and dating to the Early Jurassic, more precisely the Late Pliensbachian, about 185 million years ago. This ammonite belongs to the Amaltheidae family, a group of extinct marine cephalopods that inhabited the oceans during the Jurassic. The species is particularly interesting for its morphology and for the role it has played in studies dedicated to reconstructing ancient European marine environments. The Amaltheus margaritatus shell features a planispiral coiling, with progressively wider whorls developing around the central umbilicus. The surface may show slightly arched ribbing, while one of the most characteristic elements of the genus is the crenulated ventral keel, a slender toothed ridge that runs along the outer edge of the shell. These morphological features did not serve only a structural function: today they represent important diagnostic elements used by paleontologists to distinguish different species and evolutionary forms of ammonites. During the Early Jurassic, much of Western Europe was occupied by marine basins connected to the ancient Tethys Ocean and to northern epicontinental seas. In these environments ammonites were an important component of the fauna, alongside belemnites, bivalves, crinoids, and many other organisms. Amaltheus margaritatus also holds particular scientific interest in stratigraphy. Its name is linked to the Margaritatus Zone, a biostratigraphic subdivision of the Late Pliensbachian. Ammonites represent some of the most important guide fossils of the Mesozoic: their relatively rapid evolution and wide geographic distribution allow comparison and correlation of sedimentary successions even across great distances. A historically interesting detail concerns the species name itself. Amaltheus margaritatus was described by Denis de Montfort in 1808, at a time when the systematic study of fossils was contributing to transforming our understanding of Earth’s history. Today, a reference specimen of the species, designated as the neotype, is conserved in the collections of the Muséum national d’Histoire naturelle in Paris and originates from Normandy. The fossil has been turned into a pendant through a mounting in Sterling Silver 925, enabling its use as jewelry while preserving its paleontological character. The metalworking links two materials with drastically different histories: a precious alloy shaped by humans and the mineralized structure of an organism that lived in prehistoric seas. The spiral of the ammonite is not merely an ornamental form. It is testimony to its biological development: during growth, the animal progressively built new portions of the shell, abandoning the older chambers, which were separated by internal walls called septa. This system contributed to buoyancy regulation, allowing the ammonite to live in the water column. Today that same natural architecture becomes the centerpiece of a jewelry piece that unites paleontology, natural history, and artisanal craftsmanship. A small fragment of the ancient Jurassic seas, preserved for about 185 million years and transformed into something to wear.