Description
Genuine Dimorphinites Ammonite Fossil
This genuine ammonite fossil is identified as Dimorphinites dimorphus and comes from Port-en-Bessin in Calvados, Normandy, France. It dates to the Upper Bajocian Stage of the Middle Jurassic and is a carefully selected specimen with useful species, age, and locality information. The photographs show the exact fossil offered for sale, so the ammonite pictured is the specimen you will receive.
Dimorphinites dimorphus was an extinct marine cephalopod with a chambered, coiled shell. As the animal grew, it constructed progressively larger chambers around the outer whorl. The living ammonite occupied the final body chamber, while the older sealed chambers contributed to buoyancy control. Ammonites were relatives of living squid, cuttlefish, and nautiluses, but belonged to their own extinct branch of cephalopods.
Upper Bajocian Geological Age
The Bajocian is a stage within the Middle Jurassic Period. During this interval, extensive marine environments supported diverse ammonite communities. Their shells accumulated in sea-floor sediments and could be preserved when burial protected them from complete destruction. Over immense spans of time, compaction and mineralisation transformed the sediment into rock and preserved the fossil.
Ammonites evolved rapidly and were distributed across broad marine areas, which makes them especially valuable to geologists. Characteristic genera and species can help compare rock sequences and establish their relative ages. The supplied Upper Bajocian age therefore gives this specimen a meaningful place within the Jurassic succession and makes it useful for a collection arranged by geological stage.
Port-en-Bessin, Calvados
Port-en-Bessin lies on the Normandy coast in the Calvados department of northern France. Jurassic sedimentary rocks exposed in this region record ancient marine conditions and preserve a varied fossil fauna. A specimen with a documented locality carries more scientific and collecting value than an unlocalised decorative fossil because its place of origin connects it to a particular geological succession.
The shell’s natural colour, matrix, texture, and any small irregularities reflect its history of burial and fossilisation. Natural breaks, mineral veins, areas of surrounding rock, and differences in surface preservation are genuine characteristics of the specimen rather than features of a manufactured replica.
Shell Form and Collectable Detail
Dimorphinites ammonites are studied through the proportions and ornamentation of their coiled shells. Examine the photographs for the visible whorls, ribbing, shell outline, and preserved surface features on this individual piece. Changes in rib strength, whorl expansion, and the shape of the outer shell are among the details used when comparing ammonites.
The name Dimorphinites also reflects the long-standing scientific interest in differing adult shell forms among ammonites. Distinct mature forms can provide evidence about growth and life history. This makes the specimen engaging not only as a display fossil but also as a starting point for learning about ammonite development, classification, and Jurassic marine ecology.
Exact Specimen, Size and Authenticity
Full sizing is shown in the photographs, which provide the clearest scale and condition information for this individual fossil. The images are not stock photographs and do not represent a similar example. They show the exact Dimorphinites dimorphus ammonite that will be supplied.
This is a genuine fossil specimen and includes a generic Certificate of Authenticity card with a lifetime guarantee. It has been carefully chosen for its identifiable shell form, Upper Bajocian age, and Port-en-Bessin provenance. It makes a distinctive addition to a cabinet collection, educational display, office, study, or gift for anyone interested in authentic Jurassic fossils and the geology of Normandy.
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