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 a superb 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 natural specimen, with photographs showing the exact fossil you will receive. Full sizing and scale can be clearly seen in the images provided.

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 – 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 used as an index fossil due to its distinctive morphology and stratigraphic range. Specimens from Dorset are especially prized for their exceptional preservation and their importance in British Jurassic palaeontology.

Morphology and Diagnostic Characteristics

This specimen displays the defining features of Promicroceras, including:

• Tight, planispiral coiling with excellent symmetry
• Bold, evenly spaced radial ribbing across the shell flanks
• A compact whorl profile with clear growth lines
• Strong surface definition preserved in mineral detail

These features make Promicroceras an instantly recognisable and visually appealing ammonite, ideal for collectors, educational displays, and scientific interest.

Golden Pyrite Preservation

One of the most striking aspects 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 fine marine sediments of the Jurassic seabed. Over millions of years, pyrite replaced or infilled the original shell material, preserving delicate surface detail while producing a shimmering metallic gold finish.

Golden pyrite ammonites from the Black Ven Marls are especially sought after because they combine strong scientific value with outstanding aesthetic appeal. The reflective pyrite highlights the ribbing and shell contours, 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 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 form part of the UNESCO World Heritage-listed Jurassic Coast, one of the most important fossil regions in the world. Fossils from this locality have been collected and studied for over two centuries and remain central to understanding Jurassic marine ecosystems, sedimentology, and ammonite evolution.

Collector, Educational, and Display Value

Promicroceras 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 compact size, bold ribbing, and golden pyrite mineralisation makes this specimen both visually impressive and scientifically meaningful.

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 world’s most celebrated fossil localities.