Osperlioceras alternans Ammonite Fossil France Jurassic with COA

Description

Osperlioceras alternans Ammonite Fossil

A Genuine Lower Jurassic Fossil from France

This authentic ammonite fossil is identified as Osperlioceras alternans and comes from Aveyron in the Occitanie region of southern France. It dates to the Toarcian stage of the Lower Jurassic, linking it to an ancient marine environment around 180 million years old. The listing photographs show the exact specimen offered for sale, so its shell form, ornament, matrix and natural condition can be examined before purchase. Full dimensions are provided in the dedicated sizing photograph.

Toarcian Geology

The Toarcian was the final stage of the Early Jurassic and lasted from approximately 182.7 to 174.1 million years ago. During this interval, large areas of western Europe were covered by warm epicontinental seas connected to the developing Tethys Ocean. Sediment accumulated across shallow shelves and deeper basins, preserving the remains of ammonites and many other marine organisms. These fossil-bearing rocks now provide a detailed record of environmental change and biological evolution during the Jurassic.

Aveyron lies within a geologically varied part of southern France where Jurassic sedimentary sequences are well exposed. Fossils collected with regional and stratigraphic information retain a valuable context because they can be related to a defined place and interval of time. This specimen is therefore more than an attractive spiral form: it is direct evidence of the marine ecosystem that once occupied the region now known as Occitanie.

About Osperlioceras alternans

Osperlioceras is a Toarcian ammonite recognised through characteristics of its coiled shell, whorl proportions, ornament and sutures. Osperlioceras alternans represents one part of the remarkable ammonite radiation that occurred in Early Jurassic seas. Its shell grew by adding material around the aperture, producing a logarithmic spiral while the internal chambered portion increased behind the living animal. Surviving ribbing and other surface details record aspects of that growth.

Ammonites were extinct marine cephalopods related to modern squid, cuttlefish and nautiluses. The animal occupied the outer body chamber, while the older shell was divided by septa into a series of sealed chambers. By controlling fluids and gases within this chambered shell, the ammonite could manage buoyancy and move through the water column. The complex junctions between septa and the outer shell created suture patterns that are important in palaeontological classification.

Because ammonites evolved quickly and were distributed widely through ancient seas, they are among the most useful fossils for correlating and dating marine sedimentary rocks. A named Toarcian specimen such as this Osperlioceras alternans therefore offers both decorative appeal and genuine scientific interest.

Natural Preservation and Condition

This fossil has experienced burial, mineralisation, compaction, erosion and eventual discovery. It may show natural matrix, weathered areas, mineral colour, small losses, fine cracks or uneven surfaces. These characteristics are part of the specimen’s geological history and should not be regarded as modern manufacturing defects. Please review every photograph carefully because the images provide the clearest guide to its individual preservation. The specimen pictured is the exact fossil you will receive, and no substitute will be supplied.

For Collectors and Education

This French Jurassic ammonite is suitable for a fossil collection, geology cabinet, palaeontology display or educational study set. Its species identification, Toarcian age and Aveyron provenance make it particularly relevant to collectors interested in European ammonites, Lower Jurassic marine life, French geology or cephalopod evolution. It can also make a thoughtful gift for a fossil enthusiast, geology student, natural-history collector or admirer of prehistoric oceans.

Authenticity and Recorded Provenance

This is a carefully selected genuine fossil specimen. It includes a generic Certificate of Authenticity card carrying a lifetime guarantee of authenticity. The documented provenance is Toarcian, Lower Jurassic, Aveyron, Occitanie, France. Keeping this information with the specimen will preserve an important part of its scientific and historical value. The photographs show the actual Osperlioceras alternans offered here, while the sizing image provides the measurements required for storage or display planning.