Chondroceras polypleurum Ammonite Fossil Lower Bajocian Normandy France

Description

Chondroceras polypleurum Ammonite Fossil from Normandy

Genuine Jurassic Fossil Specimen

This carefully chosen Chondroceras polypleurum ammonite is a genuine fossil from Caen in the Calvados department of Normandy, France. The photographs show the actual specimen that you will receive, so its individual preservation, colour, matrix and surface detail can be considered before purchase. Please use the sizing photograph for the specimen’s full measurements and proportions.

Lower Bajocian Geological Age

This ammonite dates from the Lower Bajocian, an interval of the Middle Jurassic Period approximately 170 million years ago. During the Bajocian, much of north-western Europe was covered by warm, shallow marine seas. Sediments accumulated on the sea floor and preserved a rich fauna of ammonites, bivalves, brachiopods and other marine organisms. The rocks around Caen and wider Calvados record these ancient environments and have long been studied for their varied Jurassic fossils.

When an ammonite died, its shell could settle onto the seabed and become buried by lime-rich mud or other sediment. With continued burial, compaction and mineralisation gradually transformed the surrounding sediment into rock while preserving the shell or an internal mould. Natural changes during fossilisation account for the specimen’s texture, colour, mineral deposits and any incomplete areas.

Species and Fossil Characteristics

Chondroceras polypleurum belongs to the Ammonoidea, the extinct group of coiled marine cephalopods that flourished through much of the Mesozoic Era. Ammonites were relatives of modern cephalopods such as squid, cuttlefish, octopus and nautilus. Their shells were divided internally into chambers by septa, with the living animal occupying the final body chamber. A connecting tube called the siphuncle helped regulate buoyancy.

Chondroceras is classically associated with the family Stephanoceratidae within the order Ammonitida. Members of this group are recognised by evolute to moderately involute coiling and strong ornamentation. Chondroceras specimens commonly display well-defined ribs and a robust shell form, features that make the genus appealing for both scientific study and display. The species name polypleurum refers to its characteristic many-ribbed appearance.

Ammonites evolved rapidly and were widespread in Jurassic seas, making them valuable index fossils. Their presence helps geologists correlate rock layers and refine the relative age of marine deposits. A correctly localised specimen therefore provides information not only about an extinct animal but also about the geological history of Normandy.

Collecting and Display Appeal

This French Jurassic ammonite is well suited to a fossil collection, geological teaching display, cabinet of curiosities or natural history arrangement. It also makes a thoughtful gift for an ammonite collector, geology student or anyone fascinated by prehistoric marine life. Its natural form and authentic locality give it a character that cannot be reproduced by manufactured decorative pieces.

Authenticity and Care

This is a genuine fossil specimen and includes a generic Certificate of Authenticity card with a lifetime guarantee. Handle it carefully over a soft surface and support the matrix rather than lifting it by any projecting feature. Keep it dry and away from strong chemicals, repeated impacts and rapid environmental changes. Natural fissures, irregular edges, weathering and mineral variation are expected features of an authentic fossil and form part of its geological story.