Rare Plesiospitidiscus ligatus Ammonite Fossil from Barremian Cretaceous Drome Region France Authentic Specimen

Description

Geological Context and Provenance

This exceptional specimen is a genuine Plesiospitidiscus ligatus fossil ammonite from the Barremian Stage of the Early Cretaceous Period, dating to around 129 – 125 million years ago. It originates from the Drôme region of southeastern France, an area world-renowned for producing superbly preserved ammonites from Lower Cretaceous strata. These deposits formed along the northern margins of the ancient Tethys Ocean, where shallow marine environments supported flourishing ammonite populations.

The Barremian represents a pivotal time in Earth’s history, characterised by diversification among ammonites and other marine fauna. Fossils from the Drôme are invaluable in reconstructing the palaeogeography of the Early Cretaceous and continue to be of major interest to palaeontologists and collectors worldwide.

Fossil Type and Species Information

Plesiospitidiscus ligatus is a distinctive ammonite belonging to the Order Ammonitida, Superfamily Desmoceratoidea, and Family Desmoceratidae. This group is known for its moderately involute shells and complex ribbing patterns that make them easily recognisable among Cretaceous ammonites.

The genus Plesiospitidiscus has been studied extensively due to its biostratigraphic significance within Barremian sequences. The species ligatus is particularly noted for its detailed ribbing, which forms a defining characteristic of the shell morphology. These features, combined with its restricted stratigraphic range, make it an important index fossil for the Lower Cretaceous, enabling accurate correlation of sedimentary layers across Europe and beyond.

Morphological Features and Identification

This specimen displays the typical features of Plesiospitidiscus ligatus, including sharp ribbing that extends across the flanks and continues to the venter. The whorls are moderately compressed, giving the fossil a distinctive and elegant coiled appearance. In some examples, the ribs may bifurcate, adding to the ornamental quality of the shell.

These morphological traits were adaptations to life as a nektonic predator in open marine waters. The ribbing likely served both a structural purpose in reinforcing the shell and a hydrodynamic role in stabilising the ammonite as it swam. For collectors, these features make P. ligatus not only a scientifically important species but also a visually striking fossil.

Depositional Environment

During the Barremian, the Drôme region was situated along a shallow marine shelf influenced by the warm waters of the Tethys Ocean. Fine-grained limestone and marl deposits accumulated in this setting, providing excellent preservation conditions for ammonites. These seas supported a rich variety of marine life, including belemnites, bivalves, gastropods, and marine reptiles, with ammonites serving as a vital part of the food chain.

The preservation of Plesiospitidiscus ligatus in these sediments highlights the stability of this depositional environment, where periodic burial events allowed ammonite shells to be encapsulated and fossilised with their characteristic ornamentation intact.

Collector Appeal and Authenticity

This specimen of Plesiospitidiscus ligatus is a rare and valuable fossil from one of Europe’s most important Cretaceous localities. Its elegant ribbing and classic Barremian provenance make it an excellent addition to any serious fossil collection, educational display, or natural history showcase.

• 100% Genuine Specimen – Every fossil we supply is authentic and comes with a Certificate of Authenticity.
• Exact Fossil Shown – The photographs depict the actual specimen you will receive.
• Scale Reference – Scale rule squares / cube = 1 cm. Please refer to photos for full sizing.

This ammonite fossil offers the opportunity to own a tangible piece of Early Cretaceous history, combining both scientific value and natural beauty. Its rarity, provenance, and detailed preservation ensure it will be a treasured specimen for collectors, enthusiasts, and educators alike.