Description
Genuine Davidiceras potieri Ammonite Fossil
This carefully chosen fossil is a genuine Davidiceras potieri ammonite from France. The species is recognised from the Lower Cretaceous, specifically the Barremian Stage, rather than the Lower Bajocian of the Middle Jurassic. Published examples place Davidiceras potieri within Barremian marine deposits of southern France, so the geological age and Givry locality originally associated with this specimen should be checked against its collection label before sale.
The photograph shows the actual fossil specimen you will receive, allowing its individual shape, preservation, ornamentation, colour, matrix and natural geological features to be examined before purchase. Full sizing and proportions can be seen in the accompanying photograph.
This authentic fossil includes a generic Certificate of Authenticity card with a lifetime guarantee.
Fossil Classification and Geological Information
Scientific name: Davidiceras potieri
Fossil type: Ammonite
Phylum: Mollusca
Class: Cephalopoda
Subclass: Ammonoidea
Order: Ammonitida
Superfamily: Desmoceratoidea
Geological period: Cretaceous
Epoch: Early Cretaceous
Stage: Barremian
Country of origin: France
Davidiceras potieri was originally described by Philippe Matheron in 1879. The genus Davidiceras is placed among desmoceratoid ammonites, although published classifications differ over whether it belongs within the Barremitidae or is treated within a more broadly defined Desmoceratidae.
Ammonites are especially important to palaeontologists because their shell forms changed rapidly through geological time. Particular species can therefore help identify the relative age of marine sedimentary rocks and allow fossil-bearing strata from different regions to be compared.
Davidiceras Shell Form and Morphology
Davidiceras potieri is noted for its comparatively inflated and robust shell form. The coiled shell may appear broad and rounded, with substantial whorl thickness relative to its diameter. Published specimens have been described as strongly swollen or globose, producing a distinctive profile among Barremian ammonites.
The shell grew in a flat spiral around a central umbilicus. Each successive whorl partly enclosed the earlier growth, while the final and largest section formed the living chamber occupied by the animal. Depending on preservation, the fossil may display portions of the inner whorls, rounded flanks, ventral margin and natural shell ornamentation.
The strength of any ribs, growth lines or constrictions can vary according to the animal’s growth stage and the condition of the fossil. Surface detail may also be affected by mineral replacement, weathering, compression or the preservation of the ammonite as a sediment-filled internal mould.
Natural fractures, attached matrix, incomplete areas, mineral deposits and variations in colour are expected characteristics of genuine fossils. These features reflect the specimen’s individual history of burial and preservation rather than modern manufacture.
Barremian Stage of the Lower Cretaceous
The Barremian is a stage of the Early Cretaceous that predates the Aptian and Albian. During this interval, extensive marine environments covered parts of what is now France, supporting diverse ammonites, nautiloids, belemnites, bivalves, gastropods, brachiopods and other marine organisms.
Davidiceras potieri is recorded from Lower Barremian deposits and has been associated with ammonite intervals including the Pulchella Zone and its lower part near the Nicklesi Zone. These zones are based on characteristic ammonite assemblages and allow palaeontologists to divide the Barremian into more precise units of geological time.
The animal lived in a marine ecosystem more than 120 million years ago, when changing sea levels and sedimentary conditions produced extensive limestone and marl successions across southern and south-eastern France.
Life of a Cretaceous Ammonite
Ammonites were extinct marine cephalopods related to modern squid, cuttlefish, octopuses and nautiluses. The living animal occupied the final outer chamber of its shell, while the older coiled portion was divided into smaller chambers by curved walls called septa.
A narrow tube known as the siphuncle passed through these chambers. By regulating the proportions of liquid and gas within them, the ammonite could control its buoyancy and maintain its position within the water column.
Movement was achieved by drawing water into the mantle cavity and expelling it through a muscular funnel. This jet-propulsion system allowed the animal to move through the sea, while tentacles around the mouth were probably used to capture small prey and explore its surroundings.
The chambered shell enlarged continuously throughout life. New shell material was added at the aperture, and additional septa formed behind the animal as it moved forwards into a newly expanded living chamber.
Natural Fossilisation and Preservation
After death, the ammonite shell settled onto the Cretaceous seabed. Its soft tissues decayed while sediment accumulated around and within the empty shell. Burial helped protect the remains from currents, scavengers and complete physical destruction.
Over millions of years, pressure compacted the surrounding sediment into rock. Mineral-rich groundwater could alter, replace or dissolve the original aragonitic shell. Sediment filling the chambers hardened into an internal cast capable of preserving the ammonite’s coiled form even when much of the original shell material had disappeared.
The photograph shows the exact carefully chosen fossil specimen you will receive. Full sizing is shown in the photo. A generic Certificate of Authenticity card with a lifetime guarantee is included.
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