Promicroceras Multi Calcite Ammonite Fossil Block Jurassic Lyme Regis Dorset UK

Description

Authentic Promicroceras Multi Ammonite Block from the Jurassic Coast

Offered here is a genuine Promicroceras multi block calcite ammonite fossil, collected from the famous Black Ven Marls at Stonebarrow Cliff, Charmouth, Lyme Regis, Dorset, along England’s world-renowned Jurassic Coast. This naturally formed fossil block preserves multiple Promicroceras ammonites together within their original Lower Jurassic matrix, creating a visually striking and scientifically informative specimen. The photographs show the exact fossil you will receive, carefully selected for preservation quality, balance, and overall presentation. Full sizing details are shown in the photos.

This fossil is a genuine specimen and includes a Certificate of Authenticity lifetime guarantee generic card, providing lasting confidence in provenance and collectability.

Provenance and Professional Preparation

This specimen was discovered by our own team members, Alister and Alison, on 18 December 2025 during fieldwork at Stonebarrow Cliff. Following recovery, the fossil block was cleaned, prepared, and stabilised by Alison, ensuring the ammonites are clearly visible while retaining the integrity of the original matrix. Team-collected provenance provides a strong, traceable history and adds significant value for collectors who appreciate documented discovery and preparation.

Geological Formation and Age

The fossil originates from the Lower Lias Group, deposited during the Early Jurassic Period, approximately 199–191 million years ago, within the Sinemurian Stage. The Black Ven Marls are composed of fine-grained marine mudstones and marls laid down in a shallow epicontinental sea that once covered southern Britain. Stonebarrow Cliff is one of the most important Lower Jurassic fossil localities in Europe and is internationally recognised for its abundance of ammonites that underpin Jurassic stratigraphy.

Fossil Species and Scientific Context

The ammonites preserved within this block belong to the genus Promicroceras, part of the Order Ammonitida, Superfamily Eoderoceratoidea, and Family Echioceratidae. Promicroceras is a classic Lower Lias index fossil, closely associated with the Promicroceras biozone, making it particularly important for biostratigraphic correlation of Early Jurassic marine sediments. Multi-specimen blocks of Promicroceras are especially valued, as they preserve multiple individuals in close association, reflecting original sea-floor accumulation rather than isolated finds.

Morphology and Calcite Preservation

The ammonites display characteristic planispiral coiling with compact, evolute shells and strong, regular ribbing across the flanks. Rib spacing and strength are clearly visible, allowing observation of growth stages and shell ornamentation. Calcite mineralisation enhances surface detail and gives the ammonites a pale, crystalline appearance that contrasts attractively with the darker marl matrix. Preservation within a single block maintains the natural spatial relationship between the ammonites, increasing both scientific integrity and visual appeal.

Depositional Environment

During the Early Jurassic, the Charmouth and Lyme Regis area lay beneath a warm, shallow marine environment rich in ammonites, belemnites, fish, and marine reptiles. Periodic storm events and sediment influx caused ammonite shells to accumulate on the sea floor. Rapid burial by fine sediments, combined with low-oxygen conditions, reduced scavenging and disturbance, allowing multiple ammonites to be preserved together within the Black Ven Marls. This fossil block represents a genuine snapshot of an Early Jurassic marine assemblage.

Collecting, Display, and Educational Value

This Promicroceras multi block calcite ammonite fossil is ideal for serious fossil collectors, educational collections, museum displays, or refined interior presentation. Its combination of multiple ammonites, classic British Jurassic provenance, team-documented discovery, and clear stratigraphic significance makes it both scientifically informative and visually compelling. Multi-ammonite blocks from Stonebarrow Cliff are increasingly scarce and highly sought after. Each specimen we offer is individually selected to ensure you receive an authentic and carefully curated piece of Early Jurassic marine history from one of the world’s most important fossil coastlines.