Description
Authentic Cardioceras (Scoticardioceras) excavatum Fossil Ammonite
Presented here is a fine fossil ammonite specimen of Cardioceras (Scoticardioceras) excavatum, from the Lower Oxfordian Stage of the Jurassic Period, found at Novion Porcien in the Ardennes, France. This ammonite dates back approximately 163 to 157 million years, making it an exceptional piece of natural history. The specimen shown in the photographs is the exact fossil you will receive, supplied with a Certificate of Authenticity. Its sharp detail and excellent preservation make it both scientifically significant and visually appealing.
Geological Context
The Oxfordian Stage, which marks the beginning of the Upper Jurassic, was a time of dynamic marine ecosystems and wide distribution of ammonites across Europe. The Lower Oxfordian deposits of the Ardennes region are particularly renowned for their diversity of Cardioceras ammonites, which serve as important index fossils for correlating Jurassic rock sequences.
The locality of Novion Porcien is part of a region that has yielded many significant Jurassic marine fossils. The fine-grained sediments deposited in this shallow seaway created ideal conditions for the preservation of ammonites, allowing their intricate shell structures and ribbing to remain visible millions of years later.
Scientific Classification
- Species: Cardioceras (Scoticardioceras) excavatum
- Genus: Cardioceras
- Subgenus: Scoticardioceras
- Family: Cardioceratidae
- Superfamily: Stephanoceratoidea
- Order: Ammonitida
- Class: Cephalopoda
- Geological Stage: Lower Oxfordian, Jurassic (~163–157 million years ago)
- Locality: Novion Porcien, Ardennes, France
Morphological Features
Cardioceras (Scoticardioceras) excavatum is characterised by its strongly ribbed, evolute shell, with ribs that often bifurcate and extend cleanly across the whorls. The whorls are relatively broad, with well-developed ornamentation that provides a highly diagnostic appearance. The robust ribbing and symmetry of the shell make this ammonite easily recognisable to collectors and palaeontologists.
Ammonites of this subgenus were free-swimming marine cephalopods, related to modern squid and cuttlefish, that thrived in open marine environments. Their coiled shells served as both buoyancy devices and protective homes, allowing them to flourish in Jurassic seas.
Stratigraphic and Scientific Importance
Ammonites belonging to Cardioceras and its subgenera such as Scoticardioceras are critical biostratigraphic markers for the Lower Oxfordian. They provide precise dating and correlation across different parts of Europe. Fossils such as C. excavatum are widely used by geologists to define and correlate biozones, making them highly valuable in the study of Jurassic stratigraphy.
This specimen from Novion Porcien, with its well-preserved features, exemplifies the importance of the Cardioceratidae in Oxfordian faunal succession. Collectors and researchers alike value such specimens for both their scientific and educational significance.
Depositional Environment
The Ardennes region during the Oxfordian was dominated by warm, shallow marine environments, part of the epicontinental seas that covered much of Europe. Fine sedimentation helped preserve organic and shell material, while the relatively calm depositional setting allowed fragile ammonite shells to be fossilised with minimal distortion. The preservation seen here reflects those favourable geological conditions.
Collector and Display Value
This Cardioceras (Scoticardioceras) excavatum ammonite is not only an important index fossil but also a visually striking specimen. Its strong ribbing and classic Jurassic ammonite morphology make it a superb display fossil for collectors, educators, or anyone with an appreciation for ancient marine life.
- Type: Fossil Ammonite – Cardioceras (Scoticardioceras) excavatum
- Age: Lower Oxfordian, Jurassic (~163–157 million years ago)
- Location: Novion Porcien, Ardennes, France
- Scale: Rule squares/cube = 1 cm (see photographs for accurate sizing)
- Authenticity: 100% genuine specimen with Certificate of Authenticity
- Guarantee: The exact fossil pictured is the one you will receive
A fine and authentic example of a Jurassic ammonite, this specimen represents both a remarkable relic of Earth’s deep history and an impressive addition to any fossil collection.
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