Ptychophylloceras semisulcatum Ammonite Fossil Valanginian Cretaceous France Authentic COA

Description

Ptychophylloceras semisulcatum Ammonite Fossil

This listing features a beautifully preserved Ptychophylloceras semisulcatum Ammonite Fossil from the Valanginian stage of the Early Cretaceous, discovered in Isère, France. Dated at around 135 million years old, this specimen provides a direct link to the marine ecosystems of the Early Cretaceous. The fossil displayed in the photographs is the actual piece you will receive, photographed with a 1 cm scale cube for precise measurement reference. Every fossil we sell is 100% genuine and comes with a Certificate of Authenticity.

Geological Context – Isère, France

The fossil originates from the Valanginian deposits of Isère, a region in southeastern France that has long been celebrated for its rich fossil heritage. During the Early Cretaceous, this area formed part of a shallow marine environment bordering the Tethys Ocean. Layers of limestone and marl were deposited in these basins, creating conditions ideal for the preservation of ammonites and other marine life. The Valanginian stage is a key subdivision of the Lower Cretaceous, making fossils from this interval essential for understanding the evolutionary history of ammonites as they diversified after the Jurassic.

Species Overview – Ptychophylloceras semisulcatum

This fossil is identified as Ptychophylloceras semisulcatum, belonging to the order Ammonitida, superfamily Phyllocerataceae, and family Phylloceratidae. Ammonites in this group are characterised by their smooth to weakly ornamented shells with distinctive suture patterns, a feature that distinguishes them from the more heavily ribbed ammonites of other families.

Ptychophylloceras semisulcatum exhibits a moderately involute shell with gently curving whorls and a delicate, often semi-smooth surface. The subtle ornamentation and complex sutures provide important diagnostic features for paleontologists. This morphology suggests a pelagic lifestyle in deeper marine environments, with the shell structure optimised for buoyancy and stability in open water.

Paleontological Importance

Ptychophylloceras semisulcatum is a scientifically valuable ammonite due to its role in biostratigraphy. Species of the Phylloceratidae are important for defining zones within the Valanginian stage, which in turn allow geologists to correlate marine deposits across Europe and beyond. The genus Ptychophylloceras represents a lineage that survived major evolutionary turnovers, linking Jurassic forms to those that thrived throughout the Cretaceous.

This specimen is also significant in highlighting ecological diversity among ammonites. Unlike more robust or heavily ornamented genera, Ptychophylloceras demonstrates evolutionary adaptation toward streamlining and subtle ornamentation, reflecting a different ecological niche within Early Cretaceous seas.

Collector’s and Educational Value

This Ptychophylloceras semisulcatum ammonite fossil is an excellent acquisition for collectors of rare Early Cretaceous ammonites. Its elegant form and scientific importance make it suitable for both display and study. For educators and students, it serves as a tangible example of ammonite diversity and evolutionary adaptation during the Valanginian stage.

Guarantee of Authenticity

• 100% genuine Ptychophylloceras semisulcatum ammonite fossil
• Supplied with a Certificate of Authenticity
• The photographed specimen is the exact fossil you will receive

This is a rare opportunity to own a scientifically significant and beautifully preserved Ptychophylloceras semisulcatum Ammonite Fossil from the Valanginian of Isère, France, a remarkable piece of natural history from the Early Cretaceous seas.