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 outstanding Promicroceras golden pyrite ammonite fossil, collected from the celebrated Black Ven Marls at Stonebarrow Cliff, Charmouth, along the world-famous Jurassic Coast at Lyme Regis, Dorset, UK. This is a carefully chosen, naturally preserved specimen, with photographs showing the exact fossil you will receive. Full sizing and proportions can be clearly seen in the images provided.

This fossil is supplied with 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 character.

Fossil Type and Species – Promicroceras

Promicroceras is a classic 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 epicontinental seas covered much of southern Britain.

Promicroceras is particularly significant in Early Jurassic biostratigraphy and is widely recognised as an important index fossil. Its relatively narrow stratigraphic range and distinctive morphology make it valuable for correlating Lower Lias marine deposits across the UK and Europe.

Morphology and Diagnostic Characteristics

This specimen displays the defining features of Promicroceras, including:

• Tight, planispiral coiling with strong bilateral symmetry
• Bold, evenly spaced radial ribbing extending across the shell flanks
• A compact, rounded whorl profile
• Clear growth lines reflecting natural shell development

These features give Promicroceras a striking and instantly recognisable appearance. The crisp preservation allows the shell ornamentation to be easily observed, making this fossil ideal for both close study and visual display.

Golden Pyrite Preservation

One of the most desirable aspects of this fossil is its natural golden pyrite mineralisation. Pyrite formed when iron and sulphur combined under low-oxygen conditions within the fine marine sediments of the Jurassic seabed. Over millions of years, pyrite replaced or infilled the original shell material, preserving fine surface detail while producing a distinctive metallic gold finish.

Golden pyrite ammonites from the Black Ven Marls are especially sought after by collectors, as they combine scientific importance with exceptional aesthetic appeal. The reflective pyrite highlights the ribbing and coiling, giving the fossil a dramatic presence under natural or display lighting.

Geological Setting – Black Ven Marls, Lower Lias

The Black Ven Marls are part of the Lower Lias succession and were deposited in a quiet offshore marine environment during the Early Jurassic. Fine-grained muds settled on the sea floor, allowing ammonites and other marine organisms to be rapidly buried and fossilised under conditions favourable for mineral replacement.

Stonebarrow Cliff and Charmouth are internationally recognised fossil localities and form part of the UNESCO World Heritage-listed Jurassic Coast. Fossils from this area have been collected and studied for over two centuries and remain central to our understanding of Jurassic marine ecosystems and ammonite evolution.

Collector, Educational, and Display Value

Promicroceras ammonites are highly desirable for:

• Fossil and ammonite collectors
• Mineral collectors drawn to 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 visually impressive and scientifically informative.

Authenticity and Provenance

• Fossil type: Promicroceras 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 most iconic fossil localities in the world.