Oxynoticeras Golden Pyrite Ammonite Fossil Jurassic Dorset UK Black Ven Marls Lower Lias Stonebarrow Cliff Charmouth Lyme Regis

Description

Genuine Golden Pyrite Oxynoticeras Ammonite from the Jurassic Coast

Offered here is a striking Oxynoticeras golden pyrite ammonite fossil, collected from the famous Black Ven Marls at Stonebarrow Cliff, Charmouth, part of the world-renowned Jurassic Coast at Lyme Regis, Dorset, UK. This is a carefully chosen natural specimen, and the photographs show the exact fossil you will receive, with full sizing clearly visible in the images.

This fossil includes a lifetime Certificate of Authenticity on a generic card, guaranteeing it as a genuine natural specimen. The ammonite has been professionally cleaned, prepared, and stabilised to enhance detail while preserving its original geological integrity.

Fossil Type and Species – Oxynoticeras

Oxynoticeras is a distinctive ammonite genus from the Lower Jurassic (Lower Lias), belonging to the Order Ammonitida and Family Oxynoticeratidae. These ammonites lived during the Sinemurian Stage, approximately 195 million years ago, when warm, shallow seas covered much of southern Britain.

Oxynoticeras is particularly valued for its elegant, compressed shell form and its prominent keel, making it one of the most recognisable ammonites from the Lower Lias of Dorset. Specimens from the Black Ven Marls are highly sought after due to their scientific importance and exceptional preservation.

Morphology and Diagnostic Features

This specimen displays the classic characteristics that define Oxynoticeras, including:

• A strongly compressed and streamlined shell profile
• A sharp, well-developed ventral keel along the outer margin
• Fine ribbing and growth lines across the flanks
• Symmetrical coiling with excellent surface definition

The keel is thought to have improved hydrodynamic efficiency, suggesting Oxynoticeras was an active swimmer within Jurassic marine ecosystems.

Golden Pyrite Preservation

One of the most remarkable features of this fossil is its natural golden pyrite mineralisation. Pyrite, often called “fool’s gold,” formed when iron and sulphur combined under low-oxygen conditions within the marine sediments of the Jurassic seabed. Over millions of years, this process replaced or infilled the original shell material, preserving fine morphological detail while creating a shimmering metallic gold finish.

Golden pyrite ammonites from the Black Ven Marls are especially prized because they combine outstanding scientific value with exceptional aesthetic appeal. The reflective pyrite highlights the keel and ribbing, making this specimen a standout display fossil.

Geological Context – Black Ven Marls, Lower Lias

The Black Ven Marls were deposited in a quiet offshore marine environment during the Early Jurassic. Fine-grained muds accumulated on the sea floor, allowing ammonites and other marine organisms to be rapidly buried and fossilised under conditions favourable for pyrite formation.

Stonebarrow Cliff and Charmouth lie within the UNESCO World Heritage-listed Jurassic Coast, one of the most important fossil regions on Earth. Fossils from this locality have been collected and studied for over two centuries and remain central to understanding Jurassic marine life, sedimentology, and ammonite evolution.

Collector, Educational, and Display Value

Oxynoticeras ammonites are highly desirable for:

• Fossil and ammonite collectors
• Mineral collectors attracted to pyrite preservation
• Educational and teaching collections
• Display cabinets and curated fossil shelves

The combination of elegant shell form, sharp keel, and golden pyrite mineralisation makes this specimen both visually impressive and scientifically meaningful.

Authenticity and Provenance

• Fossil type: Oxynoticeras ammonite
• Preservation: natural golden pyrite
• Formation: Black Ven Marls, Lower Lias
• Geological age: Lower Jurassic, Sinemurian Stage
• Locality: Stonebarrow Cliff, Charmouth, Lyme Regis, Dorset, UK
• Certificate: Lifetime Certificate of Authenticity included

This fossil represents a genuine piece of Dorset’s Jurassic seabed, preserving a marine animal that lived nearly 200 million years ago, and offers a rare opportunity to own a beautifully preserved golden pyrite ammonite from one of the world’s most celebrated fossil localities.