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

Description

Genuine Golden Pyrite Crucilobiceras Ammonite from the Jurassic Coast

Presented here is a striking Crucilobiceras golden pyrite ammonite fossil, collected from the famous Black Ven Marls at Stonebarrow Cliff, Charmouth, within the internationally 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 – Crucilobiceras

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

Crucilobiceras occupies an important position within Early Jurassic ammonite successions and is valued by collectors and researchers alike for its distinctive morphology and stratigraphic relevance. Dorset specimens are particularly sought after due to the classic exposures and exceptional preservation found within the Black Ven Marls.

Morphology and Diagnostic Characteristics

This specimen displays the defining features of Crucilobiceras, including:

• A broad, evolute shell, with earlier whorls clearly visible
• Strong, well-defined radial ribbing extending across the flanks
• A robust, rounded whorl section
• Clear growth lines and natural bilateral symmetry

The bold ribbing and solid shell construction give Crucilobiceras a powerful visual presence, making it an excellent display ammonite and a strong representative of Early Jurassic shell design.

Golden Pyrite Preservation

One of the most visually impressive 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 surface detail while creating a metallic gold appearance.

Golden pyrite ammonites from the Black Ven Marls are especially prized because they combine high scientific value with outstanding aesthetic appeal. The reflective pyrite accentuates ribbing and shell contours, making this specimen particularly eye-catching under display lighting.

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

Crucilobiceras 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 bold shell morphology and golden pyrite mineralisation makes this specimen both visually impressive and scientifically meaningful.

Authenticity and Provenance

• Fossil type: Crucilobiceras 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.