Cardioceras persecans Fossil Ammonite Lower Oxfordian Jurassic Ardennes France Authentic Specimen

Description

This listing offers a genuine Cardioceras persecans ammonite fossil from the Lower Oxfordian stage of the Jurassic period (approximately 163–160 million years ago). Sourced from the Ardennes region of France, this ammonite is a superbly preserved example of the genus Cardioceras, a fossil group that plays a crucial role in defining Oxfordian stratigraphy. With its strong ribbing, distinctive coiling, and characteristic keel, this fossil demonstrates the striking features that make Cardioceras one of the most iconic ammonites of the Oxfordian. The specimen pictured is the exact fossil you will receive, shown with a 1 cm scale cube for accurate size reference. Every purchase comes with a Certificate of Authenticity, guaranteeing its status as a genuine piece of Earth’s history.

Geological and Palaeontological Context

The Oxfordian stage, part of the Upper Jurassic, was a time of widespread shallow marine environments across Europe. The Ardennes basin in France was submerged beneath epicontinental seas, creating ideal conditions for ammonites, bivalves, and other marine life to flourish. Within these marine deposits, Cardioceras fossils serve as index fossils, vital for dating and correlating Oxfordian strata across Europe.

Cardioceras persecans belongs to the family Cardioceratidae, within the superfamily Perisphinctoidea. This family is characterised by compressed shells with ribbing and a distinct keel, features that make them highly recognisable and scientifically important. The species persecans marks a zonal interval within the Lower Oxfordian, helping palaeontologists identify specific horizons within Jurassic sediments.

Morphological Features

The specimen displays the diagnostic traits of the genus Cardioceras:

• Coiling: Moderately involute shell form, with inner whorls partly concealed by later growth.
• Ribbing: Strong, evenly spaced ribs crossing the flanks, providing a striking ornamentation.
• Keel: A pronounced keel runs along the venter, enhancing the ammonite’s hydrodynamic efficiency.
• Whorl Section: Subcompressed profile with gently curved flanks and rounded shoulders.
• Sutures: Complex suture patterns, a hallmark of advanced ammonites, visible in areas of preservation.

These morphological adaptations allowed Cardioceras to function as a fast-swimming nektonic predator, preying on smaller invertebrates in the Jurassic seas.

Scientific and Collector Significance

This fossil is significant not only as a natural work of art but also as a key biostratigraphic marker. Cardioceras persecans defines part of the Cardioceras cordatum Zone, one of the most important zonal subdivisions of the Lower Oxfordian. Fossils from this interval are crucial for global Jurassic stratigraphy.

For collectors, this ammonite offers:

• A rare and desirable species from a classic French locality.
• Excellent preservation of defining features.
• Geological importance tied to the Oxfordian biozonation.
• Historic provenance from the Ardennes region, a well-known source of Jurassic fossils.

Key Details

• Species: Cardioceras persecans
• Age: Lower Oxfordian, Jurassic (~163–160 million years ago)
• Location: Ardennes, France
• Order: Ammonitida
• Superfamily: Perisphinctoidea
• Family: Cardioceratidae
• Features: Strong ribbing, pronounced keel, compressed whorls, complex sutures
• Authenticity: 100% genuine fossil with Certificate of Authenticity
• Scale Reference: 1 cm cube (see photographs for accurate sizing)

This Cardioceras persecans ammonite fossil from the Ardennes represents a rare opportunity to acquire an authentic specimen of scientific and collector importance. With its beautifully preserved features and classic locality, it is an outstanding fossil that brings the story of the Jurassic seas into your collection.

Scale cube = 1 cm. Please see photographs for full sizing details.