Description
Rare Genuine Flicticeras Ammonite Fossil
This carefully chosen fossil is a rare and genuine Flicticeras sp. ammonite from Saint-Laon, Oiron, in the Deux-Sèvres department of France. Dating from the Middle Callovian interval of the Middle Jurassic, it represents an extinct marine cephalopod that inhabited the warm European seas more than 160 million years ago.
The abbreviation “sp.” indicates that the fossil has been identified to the genus Flicticeras, but a more specific species name has not been assigned. This is a standard palaeontological convention used when the available shell features support a genus-level identification but do not permit a reliable determination at species level.
The photograph shows the actual specimen you will receive, not a stock photograph or representative example. Its individual preservation, natural colour, shell form, surface detail and associated matrix can therefore be examined before purchase. Full sizing and proportions are shown in the accompanying photographs.
Jurassic Ammonite Shell and Morphology
Like other ammonites, Flicticeras possessed a planispirally coiled external shell formed from a succession of increasingly large whorls. The proportions of these whorls, the width of the central umbilicus, the shape of the outer margin and the development of shell ornament are among the characteristics used when studying and comparing Jurassic ammonites.
Depending on preservation and growth stage, visible features may include radial ribbing, fine growth lines, constrictions, raised ornament or portions of the original whorl outline. Some details may be preserved directly on the shell surface, while others can appear as impressions or relief on the natural internal mould.
Ammonite ornamentation was not necessarily identical throughout the animal’s life. Juvenile whorls could differ from mature sections in rib strength, spacing and shell proportions. This change through growth, known as ontogenetic development, is an important consideration when palaeontologists identify incomplete or naturally weathered specimens.
Life in the Middle Jurassic Sea
Ammonites were marine molluscs belonging to the cephalopod group and were related to modern squid, cuttlefish, octopuses and nautiluses. Unlike most living cephalopods, they carried a prominent external shell that provided protection and helped regulate buoyancy.
The living animal occupied the final and largest portion of the shell, called the body chamber. Earlier parts were divided internally by curved walls known as septa, producing a sequence of chambers connected by a narrow tube called the siphuncle.
By regulating the proportions of liquid and gas within these chambers, the ammonite could control its buoyancy and maintain its position within the water column. Movement was probably achieved partly through jet propulsion, with water drawn into the mantle cavity and expelled through a muscular funnel.
Ammonites occupied an important position in Jurassic marine ecosystems. They probably consumed small crustaceans, planktonic animals and other marine prey while also serving as food for larger fish and marine reptiles.
Middle Callovian Geological Age
The Callovian is the final stage of the Middle Jurassic and preceded the Oxfordian Stage of the Upper Jurassic. The Middle Callovian represents the central part of this interval, during a time when extensive shallow seas covered large areas of western Europe.
Present-day France formed part of an archipelago surrounded by warm marine shelf environments. Layers of limestone, marl and other carbonate-rich sediments accumulated across the seabed, preserving a diverse fauna of ammonites, nautiloids, belemnites, bivalves, gastropods, brachiopods, echinoids and additional marine organisms.
Ammonites are particularly useful in Jurassic biostratigraphy because their shell forms evolved comparatively rapidly and many taxa had restricted geological ranges. Fossil assemblages can therefore help geologists compare sedimentary beds and determine their relative positions within the Callovian succession.
Saint-Laon, Oiron, Deux-Sèvres Provenance
Saint-Laon lies near Oiron in western France, within an area known for fossil-bearing Middle Jurassic sedimentary rocks. The wider region preserves deposits formed beneath the ancient marine waters that once extended across this part of Europe.
Callovian exposures around Saint-Laon have yielded a varied ammonite fauna. These fossils provide evidence of the changing marine communities and sedimentary conditions present during the Middle Jurassic. Specimens from accurately recorded localities are especially desirable because their provenance connects the fossil with a specific geological setting.
This specimen retains its recorded Saint-Laon, Oiron locality together with its identification as Flicticeras sp. and its Middle Callovian age. These details add considerable scientific, educational and collectable interest compared with an ammonite supplied without geographical or stratigraphic information.
Fossilisation and Natural Preservation
After the ammonite died, its shell descended to the Jurassic seabed and was gradually buried by sediment. Burial helped protect parts of the shell from currents, scavengers and complete physical destruction.
As further sediment accumulated, compaction and cementation transformed the deposit into sedimentary rock. Mineral-rich groundwater moved through the buried material and altered the shell during fossilisation. The original shell, composed mainly of aragonite, may have survived partly, been replaced by minerals or dissolved to leave a mould.
Sediment entering the empty shell chambers could harden and form a natural internal cast. External impressions may preserve the ribbing, growth lines and other ornament once present on the shell surface. A single fossil can display more than one preservation type.
Natural chips, fractures, incomplete areas, matrix attachment, mineral-filled cracks, surface wear and slight distortion are normal characteristics of genuine fossils. They record the specimen’s burial, mineralisation and geological history and contribute to its unique appearance.
Rare Collectable French Ammonite
This rare Flicticeras sp. ammonite is an appealing addition to a collection of French fossils, Callovian ammonites, Middle Jurassic cephalopods or prehistoric marine life. Its documented Saint-Laon provenance makes it particularly suitable for a locality collection, geological cabinet, educational display or natural-history interior.
It would also make a distinctive gift for an ammonite collector, palaeontology enthusiast or anyone fascinated by the ancient seas of Jurassic Europe.
The fossil has been individually selected, and the photograph shows the exact specimen that will be supplied. Full sizing can be seen in the accompanying images.
This is a 100% genuine fossil specimen and includes a generic Certificate of Authenticity card with a lifetime guarantee.
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