Description
Genuine Ludwigia bradfordensis Ammonite Fossil
This carefully chosen fossil is a genuine Ludwigia bradfordensis ammonite recorded from the Marnes de Dives Formation at Fresney-le-Puceux, Calvados, France. It is associated with the marine sedimentary rocks of the Middle Jurassic, an important interval in the evolutionary history of ammonites and other prehistoric sea life.
The photograph shows the actual fossil specimen you will receive, allowing you to examine its natural preservation, colour, surface detail and individual geological character before purchasing. Full sizing and scale information can be seen in the accompanying photograph.
Marnes de Dives Formation Geology
The Marnes de Dives Formation is a fossiliferous Jurassic marine deposit found in Normandy and neighbouring parts of northern France. Its name comes from Dives-sur-Mer in Calvados, where comparable strata form part of the well-known geological succession exposed along the Normandy coast.
The formation is principally composed of marl, a fine-grained sedimentary rock containing a mixture of clay and calcium carbonate. Thin limestone horizons and locally developed fossil-rich layers may also occur. These sediments accumulated in a marine basin connected to the extensive seas that covered much of western Europe during the Middle Jurassic.
Fine mud and carbonate particles settled across the sea floor, gradually burying the remains of ammonites, belemnites, bivalves, gastropods and other marine organisms. Changing water depths, sediment supply, currents and seabed conditions produced a varied sequence of fossil-bearing beds. Mineral-rich groundwater later passed through the buried sediments, contributing to the preservation and mineralisation of the fossils.
Jurassic ammonites from Normandy are highly valued for their scientific importance and their strong association with one of France’s best-known fossil-producing regions. They provide evidence of the diverse cephalopod communities that inhabited the north-west European seas millions of years ago.
Ludwigia Ammonite Form and Ornamentation
Ludwigia is recognised as a genus of planispirally coiled ammonites with a generally compressed and relatively streamlined shell form. The whorls coil around a central umbilicus, and the outer whorls may partly overlap the earlier stages of shell growth.
Species assigned to this genus typically display curved or gently sinuous ribs extending across the flanks. These ribs may vary in strength and spacing as the animal grew, creating a combination of fine ornamentation and a defined shell profile. The outer margin, known as the venter, is commonly narrow and may carry a keel that gave the shell a more sharply defined outline.
The exact appearance of an individual fossil depends on its growth stage and preservation. Earlier whorls may show finer ribbing, while the later shell can develop broader spacing or more prominent ornamentation. Natural wear, mineral replacement and the presence of surrounding matrix can also affect how much of the original shell sculpture remains visible.
The living ammonite occupied the final body chamber of the shell. Earlier portions were divided by internal walls called septa, forming a series of chambers collectively known as the phragmocone. By controlling the proportions of liquid and gas within these chambers, the ammonite could regulate its buoyancy in the Jurassic sea.
Scientific Classification
Fossil type: Ammonite
Scientific identification: Ludwigia bradfordensis
Family: Graphoceratidae
Superfamily: Hammatoceratoidea
Order: Ammonitida
Geological period: Jurassic
Geological epoch: Middle Jurassic
Geological formation: Marnes de Dives Formation
Recorded horizon: Middle Callovian
Locality: Fresney-le-Puceux, Calvados, France
Ammonites were extinct marine cephalopods related to living squid, cuttlefish, octopuses and nautiluses. Their widespread distribution and relatively rapid evolutionary changes make them valuable index fossils for studying and correlating Jurassic marine rocks.
Fossilisation and Natural Geological Features
Following the death of the ammonite, its shell settled on the seabed or was transported a short distance by currents before burial. Sediment gradually accumulated around the shell, protecting it from complete destruction. Over millions of years, compaction and mineral-rich water transformed the sediment into rock and preserved the shell as a fossil.
Any attached matrix, incomplete edges, minor fractures, mineral-filled chambers, surface weathering or variations in colour are natural features of an authentic fossil specimen. These characteristics reflect the processes of burial, mineralisation, geological pressure and eventual recovery from the host rock. They also ensure that every ammonite is a unique natural object with its own individual appearance.
Collectable French Jurassic Fossil
This Ludwigia bradfordensis ammonite would make an excellent addition to a collection of French fossils, Normandy ammonites, Middle Jurassic fossils, Calvados fossils or scientifically identified marine specimens. Its documented formation and locality make it suitable for a fossil cabinet, geological study collection, educational display or natural history-themed interior.
The specimen has been individually selected for its collectable qualities. The listing photograph shows the exact fossil that will be supplied rather than a general example.
This is a 100% genuine fossil specimen and includes a Certificate of Authenticity generic card with a lifetime guarantee.
Full sizing please see photo.
Reviews
There are no reviews yet.