Description
Genuine Grammoceras comptum Ammonite Fossil
This is a genuine Grammoceras comptum ammonite fossil from the Lower Jurassic, Toarcian Stage, collected from Aveyron, Occitanie, France. This carefully chosen fossil specimen is an attractive and scientifically interesting piece for collectors of Jurassic ammonites, French fossils, extinct marine cephalopods, natural history specimens, and well-labelled fossil display pieces.
The photograph shows the actual fossil you will receive, allowing you to view the individual preservation, colour, shell form, surface detail, matrix, and natural character of this specific specimen before purchase. Full sizing details can be seen in the photo. This fossil includes a Certificate of Authenticity lifetime guarantee generic card, confirming it as a genuine specimen.
Fossil Type, Species and Scientific Classification
Grammoceras comptum is an ammonite, an extinct marine cephalopod belonging to the order Ammonitida. Ammonites were related to modern squid, cuttlefish, octopus, and nautilus, and are among the most recognisable fossils of the Jurassic Period. Their spiral shells, varied ornamentation, and rapid evolutionary changes make them highly valued by collectors and important in palaeontology.
This specimen belongs to the genus Grammoceras and the species Grammoceras comptum. The genus is associated with Lower Jurassic ammonite faunas and is especially interesting because grammoceratid ammonites are important in the study of Toarcian marine strata. Members of this group are often noted for their elegant coiling, compressed shell form, and fine ribbing, making them desirable both as display fossils and as scientifically labelled specimens.
Geological Age and Toarcian Context
This fossil dates from the Toarcian Stage of the Lower Jurassic, approximately 184 to 174 million years ago. The Toarcian was an important interval in Jurassic history, marked by widespread marine environments across Europe and diverse ammonite faunas that are widely used for biostratigraphy. Ammonites evolved quickly and were broadly distributed, allowing geologists to use them for comparing and dating sedimentary rock layers.
During the Toarcian, much of western Europe was covered by shallow epicontinental seas. These marine environments supported ammonites, belemnites, bivalves, brachiopods, gastropods, crinoids, and other sea life. Ammonites such as Grammoceras comptum lived as active swimming cephalopods, moving through ancient Jurassic waters before their shells eventually settled onto the sea floor after death.
Aveyron, Occitanie, France Locality
This specimen comes from Aveyron in Occitanie, southern France, a region known for fossil-bearing Jurassic sedimentary rocks. French Jurassic ammonites are popular with collectors because they represent classic European marine deposits and often preserve attractive shell forms from well-studied geological intervals.
The sediments that preserve Toarcian ammonites generally formed in marine settings, often involving limestone, marl, clay-rich deposits, or other sea-floor sediments. These environments allowed ammonite shells to become buried and fossilised over millions of years. Mineralisation, compaction, and natural geological alteration gradually preserved the shell form, creating the fossil specimen seen today.
Ammonite Morphology and Natural Features
Grammoceras comptum displays the classic planispiral ammonite shell form, with the shell coiled in a flat spiral. The whorls represent successive growth stages of the animal, expanding outward as the ammonite matured. Grammoceratid ammonites are often appreciated for their refined shell proportions, ribbed ornamentation, and compressed profile.
Depending on preservation, this fossil may show curved ribbing, whorl shape, shell compression, natural mineral staining, sedimentary matrix, weathered surface detail, or subtle fossil texture. Ammonite shells were divided internally into chambers, with the living animal occupying the outer body chamber. These chambers helped with buoyancy in the water column, while the outer shell form and ornamentation are key features used in ammonite identification.
Natural details such as small fractures, surface wear, matrix attachment, colour variation, sedimentary contact marks, and mineral deposits are part of the fossil’s geological history. These features add individuality and help distinguish a genuine natural fossil from an artificial replica or modern cast.
Collecting, Display and Educational Interest
This Grammoceras comptum ammonite fossil is well suited for display in a fossil cabinet, study, classroom, office, collection drawer, natural history display, or Jurassic fossil arrangement. Its named species identification, Lower Jurassic Toarcian age, French origin, and classic ammonite form give it strong collecting appeal.
It is suitable for collectors interested in French fossils, Jurassic ammonites, extinct cephalopods, marine invertebrates, palaeontology, geology, and educational fossil specimens. The natural spiral form gives the fossil immediate visual appeal, while the geological age and locality information add scientific interest for anyone who appreciates well-contextualised fossils from prehistoric marine environments.
Authenticity and Specimen Details
This is a genuine Grammoceras comptum ammonite fossil from the Lower Jurassic, Toarcian Stage, Aveyron, Occitanie, France. It includes a Certificate of Authenticity lifetime guarantee generic card. The photo shows the actual fossil you will receive, and full sizing information can be seen in the photo.
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