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

Description

Genuine Golden Pyrite Promicroceras Ammonite from the Jurassic Coast

Offered here is an exceptional Promicroceras golden pyrite ammonite fossil, collected from the celebrated Black Ven Marls at Stonebarrow Cliff, Charmouth, along the world-famous Jurassic Coast of Lyme Regis, Dorset, UK. This is a carefully selected, visually striking specimen, with the photographs showing the exact fossil you will receive. Full sizing and scale are clearly visible in the images provided.

The specimen was discovered by our own team members, Alister and Alison, on 23 January 2026, and has been professionally cleaned, prepared, and stabilised by Alison to ensure long-term preservation and strong display quality. A lifetime Certificate of Authenticity on a generic card is included, guaranteeing this fossil as a genuine natural specimen

Species Overview – Promicroceras

Promicroceras is a classic small ammonite genus from the Lower Jurassic (Lower Lias), belonging to the Order Ammonitida, Superfamily Psiloceratoidea, and Family Eoderoceratidae. These ammonites lived during the Sinemurian Stage, approximately 195 million years ago, when warm, shallow seas covered much of what is now southern Britain.

Promicroceras is particularly well known for its tight coiling, bold ribbing, and importance in Early Jurassic ammonite zonation. Specimens from the Dorset coast are highly prized due to their excellent preservation and historical significance in British palaeontology.

Morphology and Diagnostic Features

This specimen displays the defining features of Promicroceras, including:

• A compact, planispirally coiled shell
• Strong, evenly spaced radial ribs extending across the flanks
• A well-defined whorl shape with clear growth lines
• Symmetrical form with excellent surface detail

These features make Promicroceras an instantly recognisable and attractive ammonite, ideal for both collectors and educational use.

Golden Pyrite Preservation

One of the most desirable aspects of this fossil is its natural golden pyrite mineralisation. Pyrite formed when iron and sulphur reacted under low-oxygen conditions within the Jurassic seabed sediments. Over time, pyrite replaced or infilled the original shell structure, producing a metallic gold appearance while preserving fine anatomical detail.

Pyritised ammonites from the Black Ven Marls are especially sought after, as they combine scientific importance with outstanding visual appeal. The golden colour catches the light beautifully, making this specimen a standout display piece.

Geological Setting – Black Ven Marls, Lower Lias

The Black Ven Marls were deposited in a quiet offshore marine environment during the Early Jurassic. Fine muds accumulated on the sea floor, rapidly burying marine organisms such as ammonites and creating ideal conditions for fossilisation and pyrite formation.

Stonebarrow Cliff and Charmouth lie within the UNESCO-listed Jurassic Coast, one of the most important fossil regions in the world. Fossils from this area have been collected and studied for over two centuries and remain central to our understanding of Jurassic marine life.

Collector, Educational, and Display Value

Promicroceras ammonites are highly sought after by:

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

The combination of compact size, bold ribbing, and golden pyrite mineralisation makes this specimen both accessible and highly desirable.

Provenance and Authenticity

• Fossil: Promicroceras golden pyrite ammonite
• Formation: Black Ven Marls, Lower Lias
• Age: Lower Jurassic, Sinemurian Stage
• Locality: Stonebarrow Cliff, Charmouth, Lyme Regis, Dorset, UK
• Discovered: 23 January 2026 by Alister and Alison
• Prepared by: Alison
• 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 iconic fossil localities.