Fossil Ammonite Crucilobiceras crucilobatum Upper Sinemurian Jurassic France Authentic

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Fossil Ammonite Crucilobiceras crucilobatum Upper Sinemurian Jurassic France Authentic

Long Description

Fossil Ammonite – Crucilobiceras crucilobatum

This listing features a beautifully preserved specimen of the ammonite Crucilobiceras crucilobatum, originating from France and dating to the Upper Sinemurian stage of the Early Jurassic period, approximately 196–190 million years ago. This ammonite offers both scientific significance and aesthetic appeal, making it a prized acquisition for fossil enthusiasts, collectors, and educational institutions alike. The specimen pictured is the exact fossil you will receive, with a 1 cm scale cube included to provide full and accurate sizing.

Geological Background

The Upper Sinemurian stage marks an important interval within the Early Jurassic. During this period, much of present-day Europe was submerged beneath shallow epicontinental seas. In France, Sinemurian deposits consist of richly fossiliferous limestones and marls, which yield a variety of ammonites that are critical for establishing biostratigraphic zones. These zones allow geologists to date rock layers with high precision, and Crucilobiceras crucilobatum serves as a valuable index fossil for refining the Sinemurian stratigraphic framework.

Scientific Classification

• Kingdom: Animalia
• Phylum: Mollusca
• Class: Cephalopoda
• Order: Ammonitida
• Superfamily: Eoderoceratoidea
• Family: Crucilobiceratidae
• Genus: Crucilobiceras
• Species: Crucilobiceras crucilobatum

This taxonomy places the species within a group of ammonites known for their distinctive coiling patterns and strongly ribbed shells.

Morphological Characteristics

The shell of Crucilobiceras crucilobatum is typically evolute, meaning that all whorls are visible when viewed laterally. It is characterised by sharp, well-defined ribs that radiate across the whorls, often bifurcating or branching near the outer edge of the shell. These ribs provide not only structural strength but also distinctive visual appeal. The whorls are moderately compressed, creating a profile that is both elegant and scientifically diagnostic. Such features make this ammonite an easily recognisable species, valued by paleontologists for identification purposes and by collectors for display.

Paleoenvironment and Significance

Ammonites such as Crucilobiceras crucilobatum thrived in the shallow seas of the Early Jurassic, likely inhabiting mid-water marine environments where they played an important role as active predators. Their widespread distribution and relatively short stratigraphic range make them excellent index fossils, crucial for correlating rock layers across different regions of Europe. This particular species contributes to our understanding of the paleogeography and evolutionary pathways of early ammonites, as well as the ecological conditions of the Sinemurian seas.

Provenance and Authenticity

This specimen was collected in France, a country renowned for producing high-quality ammonite fossils. It has been carefully chosen for its completeness, preservation, and scientific integrity. As with all our specimens, it comes with a Certificate of Authenticity, ensuring it is a genuine fossil and not a replica or cast. The natural detail of this ammonite makes it both a scientifically valuable specimen and a striking piece for display.

A Timeless Addition to Any Collection

Owning this ammonite is an opportunity to hold in your hands a genuine piece of Jurassic history, formed nearly 200 million years ago in ancient seas. Whether displayed in a personal collection, used in academic study, or admired as a natural artwork, this Crucilobiceras crucilobatum specimen embodies the beauty and fascination of the fossil record. Its rarity, geological importance, and striking ribbed form ensure it will stand out as a highlight in any collection of natural history.