Description
Genuine Berbericeras sekinense Ammonite Fossil
This carefully chosen specimen is a genuine Berbericeras sekinense ammonite fossil from Caen in Calvados, Normandy, France. It dates from the Lower Bathonian interval of the Middle Jurassic and represents an extinct marine cephalopod that inhabited the ancient seas of western Europe approximately 166–168 million years ago.
The combination of a named ammonite species, a precisely recorded Middle Jurassic interval and a classic Normandy locality gives this specimen strong geological, educational and collectable interest. It is an excellent choice for collectors of ammonites, French fossils, Jurassic marine life, extinct cephalopods and natural-history specimens with documented provenance.
The photograph shows the actual fossil specimen you will receive. Full sizing and scale information can be seen in the accompanying photograph.
Lower Bathonian Middle Jurassic Geology
The Bathonian is one of the four stages of the Middle Jurassic Period. During the Lower Bathonian, the region now forming Normandy was influenced by warm, shallow to moderately deep marine environments connected to the extensive Jurassic seas of western Europe.
Calcium-carbonate mud, fine mineral particles, broken shells and the remains of marine organisms accumulated across the seabed. Through burial, compaction and natural cementation, these sediments gradually became limestone, marl and other fossil-bearing sedimentary rocks.
The marine ecosystem supported a diverse range of life, including ammonites, nautiloids, belemnites, brachiopods, bivalves, gastropods, echinoids, crustaceans and other invertebrates. Ammonites were among the most distinctive and rapidly evolving animals within these seas, making their fossils especially valuable for interpreting Jurassic rock sequences.
When this ammonite died, its shell settled onto the seabed and was gradually covered by sediment. The original shell could later be mineralised, replaced or dissolved, leaving an impression, external mould or stone-filled internal representation of its chambered form. Its present colour, texture, matrix and degree of preservation are the products of millions of years of burial and geological alteration.
Berbericeras sekinense Shell Characteristics
Berbericeras sekinense possessed a planispirally coiled shell, meaning that its successive whorls developed in a single plane around a central umbilical region. The shell form and ornamentation are important features used by palaeontologists when distinguishing ammonite genera and species.
The whorls may display a relatively open or evolute style of coiling, allowing portions of the earlier growth stages to remain visible within the central umbilicus. Ornamentation can include radial ribs extending outward across the shell flanks. These ribs may vary in strength, spacing and curvature as the ammonite grows.
The preserved specimen may show sections of the inner and outer whorls, ribbed flanks, umbilical region, outer margin, internal chamber divisions or surrounding Jurassic matrix. Changes in ribbing and whorl proportions through growth are natural features of ammonite development and contribute to the specimen’s scientific interest.
Every authentic ammonite is unique. Natural variations in completeness, matrix coverage, mineral staining, surface texture and small fractures reflect both the original shell and the geological conditions that affected it after death.
An Extinct Jurassic Marine Cephalopod
Ammonites were marine molluscs related to modern squid, cuttlefish, octopuses and nautiluses. Unlike most living cephalopods, they possessed a hard external shell divided internally into a series of chambers.
The living animal occupied the final and largest part of the shell, known as the body chamber. The older chambers formed the phragmocone, which functioned as part of the ammonite’s buoyancy system. A narrow tube called the siphuncle connected these chambers and helped regulate the balance of liquid and gas within them.
As the ammonite grew, it added progressively larger chambers around the outer edge of the shell. The walls separating the chambers are known as septa. Where these septa met the outer shell, they created intricate patterns called suture lines.
Shell proportions, ribbing, whorl shape, umbilical width, ventral form and suture patterns are among the features used to identify ammonite fossils. Because ammonites evolved rapidly and were widely distributed through ancient marine environments, they are important index fossils for comparing and dating sedimentary rock layers.
Caen Fossil from Calvados, Normandy
Caen and the surrounding Calvados region are internationally recognised for their Jurassic limestone and historic fossil discoveries. The area preserves an important record of the marine environments that covered Normandy during the Middle Jurassic.
The pale building stones associated with Caen were formed from carbonate sediment deposited within these ancient seas. Fossils preserved in the regional rocks provide evidence of changing water depths, sedimentary conditions and biological communities during the Jurassic Period.
A specimen retaining its species identification, geological interval and collection locality offers greater scientific and collectable significance than an ammonite without accompanying provenance. This Berbericeras sekinense would make a distinctive addition to a specialist ammonite collection, French fossil display, educational cabinet or collection of Middle Jurassic natural-history specimens.
Actual Specimen with Certificate of Authenticity
This is a genuine fossil specimen and not a cast, replica or reproduction. It has been individually selected for its natural appearance, geological character and collectable appeal.
The photograph shows the exact Berbericeras sekinense ammonite fossil you will receive. Full sizing is shown in the photograph.
A generic Certificate of Authenticity card is included with a lifetime guarantee of authenticity, providing lasting confidence that this is a genuine Lower Bathonian ammonite fossil from the Middle Jurassic of Normandy, France.
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