Oisteroceras Ammonite Fossil Jurassic Coast Dorset UK Lower Lias Green Ammonite Beds Golden Cap Seatown Specimen Genuine COA Included

Description

Genuine Oisteroceras Ammonite Fossil – Jurassic Coast Discovery from Dorset, UK

Offered here is a stunning and authentic Oisteroceras ammonite fossil, collected from the famous Green Ammonite Beds of the Lower Lias Formation, along the world-renowned Jurassic Coast at Golden Cap, Seatown, Dorset, England. This is a carefully chosen specimen that represents one of Britain’s most iconic marine fossil localities and one of the most celebrated fossil ammonite horizons in the Lower Jurassic.

The fossil shown in the photographs is the exact specimen you will receive, with full sizing details clearly provided in the images. Every piece we offer is a genuine fossil, and this specimen includes a Certificate of Authenticity with lifetime guarantee, supplied as a generic authenticity card for permanent documentation and peace of mind.

Importantly, this ammonite was discovered by our own experienced team members, Alister and Alison, on 19 January 2026, and has been professionally cleaned, prepped, and treated by Alison, ensuring excellent presentation and long-term stability.

Geological Setting – Green Ammonite Beds, Lower Lias

This specimen comes from the Green Ammonite Beds, a highly fossiliferous interval within the Lower Lias Group, dating to the Early Jurassic, approximately 190–200 million years ago. These rocks were deposited in a shallow, warm marine sea that covered much of what is now southern Britain.

The sediments at Golden Cap consist mainly of limestone and shale layers, representing alternating phases of quieter offshore deposition and more active carbonate formation. These environments were ideal for the preservation of ammonites, which settled onto the seafloor after death and became buried rapidly in fine sediments.

Golden Cap is the highest cliff on the south coast of England and is internationally famous for producing exceptionally preserved ammonites from the Jurassic seas.

Fossil Species – Oisteroceras Ammonite

Oisteroceras is a distinctive genus of Jurassic ammonite, belonging to the extinct subclass Ammonoidea, within the class Cephalopoda. Ammonites were marine molluscs related to modern squid, cuttlefish, and nautilus, and they were among the most successful and widespread predators of the Jurassic oceans.

Oisteroceras is particularly valued by collectors due to its characteristic coiled shell form and strong ribbing patterns, which reflect the animal’s growth stages and provide important biostratigraphic information for dating Lower Jurassic rocks.

These ammonites are classic index fossils, meaning they help geologists correlate Jurassic strata across Europe and beyond.

Morphology and Display Features

This specimen preserves the natural spiral shell structure typical of ammonites, often showing pronounced ribbing and fossil detail across the whorls. The Green Ammonite Beds are well known for producing specimens with excellent preservation, sometimes retaining subtle surface textures that highlight the original shell morphology.

The fossil has been carefully prepared to reveal its shape and detail while maintaining the authenticity of the natural matrix. This makes it ideal for both display and scientific interest.

Authenticity, Provenance and Preparation

This is a 100% genuine Oisteroceras ammonite fossil, collected on the Dorset coast by our own team. The specimen was personally found by Alister and Alison and professionally prepared by Alison, ensuring it is both attractive and properly stabilised for long-term collecting.

A Certificate of Authenticity with lifetime guarantee is included with every purchase.

Perfect For Collectors, Gifts and Education

This specimen is ideal for:

• Ammonite and Jurassic fossil collectors
• Dorset Jurassic Coast enthusiasts
• Natural history and geology displays
• Unique prehistoric gifts with real provenance
• Educational teaching specimens from the Lower Jurassic

A rare opportunity to own an authentic British ammonite fossil from the legendary Green Ammonite Beds of Golden Cap, discovered and prepared by our own expert team, and preserved from an ocean nearly 200 million years old.