Cardioceras cordatum Fossil Ammonite Lower Oxfordian Jurassic Weymouth Dorset United Kingdom COA

Description

This listing is for a genuine Cardioceras cordatum ammonite fossil from the Lower Oxfordian stage of the Jurassic period (approximately 163–157 million years ago). Collected in Weymouth, Dorset, United Kingdom, this specimen represents a rare and scientifically significant ammonite from one of Britain’s classic Jurassic localities. The fossil is beautifully preserved with distinctive ribbing and coiling typical of this species. The photographs show the actual specimen you will receive, with a 1 cm scale cube included for accurate size reference. Every fossil we supply is carefully chosen, 100% genuine, and comes with a Certificate of Authenticity.

Geological Context

During the Lower Oxfordian, southern England was covered by warm shallow seas. These conditions created an environment rich in life and ideal for the preservation of marine organisms such as ammonites. The Weymouth region of Dorset is especially important within the study of the Jurassic Coast, a UNESCO World Heritage site famed for its fossil record.

The Oxfordian stage represents the beginning of the Upper Jurassic, a key period in ammonite evolution. Ammonites such as Cardioceras cordatum played a critical role in biostratigraphy, being used to define the Cordatum Zone, which marks the base of the Oxfordian in many parts of Europe. Fossils from this zone provide vital evidence for correlating Jurassic rock layers across different regions.

Morphological Features

This specimen of Cardioceras cordatum displays several important traits:

• Shell shape: Moderately involute, with inner whorls partially hidden.
• Ribbing: Strong, radiating ribs across the flanks, characteristic of the genus.
• Keel: A defined keel along the venter, aiding hydrodynamic efficiency in swimming.
• Symmetry: Classic radial symmetry with well-preserved whorl sections.
• Suture lines: Complex patterns visible in areas of preservation, representing septal divisions.

These features suggest a nektonic lifestyle, with the ammonite actively swimming in open marine waters, likely preying on smaller organisms such as plankton and crustaceans.

Scientific and Collector Importance

Cardioceras cordatum belongs to the order Ammonitida, superfamily Perisphinctoidea, and family Cardioceratidae. Its importance in ammonite stratigraphy cannot be overstated, as it defines the Cordatum Biozone, making it an essential fossil for understanding Jurassic stratigraphy in Europe.

For collectors, this specimen represents a historically and scientifically important ammonite with both academic and aesthetic value. The strong ribbing and classic Jurassic form make it a striking display piece, while its provenance from Weymouth, Dorset ties it to one of the most famous fossil-bearing coastlines in the world.

Key Details

• Species: Cardioceras cordatum
• Age: Lower Oxfordian, Upper Jurassic (~163–157 million years old)
• Location: Weymouth, Dorset, United Kingdom
• Order: Ammonitida
• Superfamily: Perisphinctoidea
• Family: Cardioceratidae
• Features: Ribbed shell, strong keel, visible sutures, involute coiling
• Authenticity: 100% genuine fossil with Certificate of Authenticity
• Scale reference: 1 cm cube (see photographs for full sizing)

This exceptional Cardioceras cordatum ammonite fossil from Weymouth combines scientific importance, natural history, and visual appeal. It is a rare opportunity to own a piece of the Jurassic Coast’s palaeontological heritage, making it an ideal acquisition for collectors, researchers, and enthusiasts of Earth’s deep history.

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