Rare 4″ Pachycardioceras robustum Fossil Ammonite – Oxfordian, Upper Jurassic, Redcliff Dorset UK – Genuine + COA

Description

A rare 4-inch Pachycardioceras robustum Fossil Ammonite, from the Oxfordian Stage of the Upper Jurassic, collected at Redcliff, Dorset, United Kingdom. This ammonite is a fine example of the genus Pachycardioceras, a robust and distinctive ammonite highly valued by collectors and researchers. The specimen shown in the photographs is the exact one you will receive, and it comes with a Certificate of Authenticity.

Fossil Type & Species:

• Type: Ammonite (extinct marine cephalopod)
• Species: Pachycardioceras robustum
• Order: Ammonitida
• Superfamily: Cardiocerataceae
• Family: Cardioceratidae

Geological Context:

• Period: Jurassic
• Epoch/Stage: Upper Jurassic – Oxfordian (approx. 163.5 to 157.3 million years ago)
• Biozone: Associated with the Cordatum Zone of the Oxfordian, important in defining ammonite stratigraphy in Europe
• Formation: Oxford Clay / Oxfordian marl-limestone successions of Dorset
• Depositional Environment: Shallow marine shelf with silty clays and carbonates, producing exceptional ammonite preservation

Locality:

• Region: Redcliff, Dorset, United Kingdom

Morphology & Features:

• Large, robust ammonite shell with broad whorls
• Coarse ribbing, many ribs bifurcating across the flanks and ventral area
• Strongly ornamented with well-defined growth lines
• Diagnostic features that distinguish Pachycardioceras robustum from related species

Scientific Notes:

• Pachycardioceras robustum is an index species of the Oxfordian Stage, first described in the 19th century
• A key taxon for Upper Jurassic ammonite biostratigraphy across Europe

Notable Details:

• Rare British ammonite with excellent preservation and display size (4 inches)
• 100% genuine, natural fossil – no restoration
• Scale Reference: Each square or cube in the image = 1cm. Please see photos for accurate sizing

Authenticity & Guarantee: All of our fossils are 100% genuine, responsibly sourced, and professionally curated. Each specimen is supplied with a Certificate of Authenticity. The fossil shown is the exact one you will receive.

This Pachycardioceras robustum ammonite is a rare and scientifically valuable fossil from the Oxfordian of Dorset – an excellent addition for collectors, researchers, or natural history displays.