Promicroceras Calcite Ammonite Multi Block Fossils Jurassic Lyme Regis Dorset UK Lower Lias

Description

Authentic Promicroceras Multi-Fossil Block from the Jurassic Coast

Offered here is a genuine Promicroceras multi block calcite ammonite fossil assemblage with associated fossil wood, collected from the Black Ven Marls at Stonebarrow Cliff, Charmouth, Lyme Regis, Dorset, along England’s world-famous Jurassic Coast. This is a naturally formed fossil block preserving multiple ammonites together with fossilised wood, providing a rare snapshot of Early Jurassic marine life and transported terrestrial material within a single specimen. The photographs show the exact fossil you will receive, and full sizing details are provided in the images.

This fossil is a genuine specimen and includes a Certificate of Authenticity lifetime guarantee generic card, ensuring confidence in provenance and long-term collectability.

Provenance and 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 that the ammonites and fossil wood are clearly visible while retaining the original matrix and natural relationships between the fossils. Direct team-collected provenance adds a strong, traceable history that is highly valued by collectors.

Geological Formation and Age

The fossil block 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 represent fine-grained marine mudstones and marls laid down in a shallow epicontinental sea covering southern Britain. Stonebarrow Cliff is a classic and highly productive locality within the Jurassic Coast, renowned for ammonites preserved with exceptional clarity and for occasional associations with fossil wood transported from nearby landmasses.

Fossil Species and Scientific Context

The ammonites within this block belong to the genus Promicroceras, a classic Early Jurassic ammonite within the Order Ammonitida, Superfamily Eoderoceratoidea, and Family Echioceratidae. Promicroceras is a well-known index fossil closely associated with the Promicroceras biozone, making specimens from this genus particularly important for biostratigraphic correlation within the Lower Lias. The presence of fossil wood alongside the ammonites adds significant palaeoenvironmental interest, illustrating interactions between marine and terrestrial systems during the Early Jurassic.

Morphology and Preservation

The Promicroceras ammonites display characteristic evolute, planispiral coiling with clearly defined whorls and bold ribbing. Calcite mineralisation enhances shell detail and contrast against the darker marl matrix, allowing multiple individuals to be easily distinguished. The fossil wood shows natural texture and grain, preserved through mineral replacement after burial. Retention of all elements within a single block preserves their original spatial relationship, enhancing both scientific value and visual impact.

Depositional Environment

During the Early Jurassic, the Stonebarrow and Charmouth area lay beneath a warm, shallow marine environment rich in ammonites, belemnites, fish, and marine reptiles. Periodic storm events and river input transported driftwood into the sea, where it settled alongside ammonite shells on the sea floor. Rapid burial by fine sediments, combined with low-oxygen conditions, limited disturbance and allowed mixed assemblages such as this to be preserved intact within the Black Ven Marls.

Collecting, Display, and Educational Value

This Promicroceras multi block calcite ammonite fossil with fossil wood is ideal for serious fossil collectors, educational collections, museums, or statement interior display. Its combination of multiple ammonites, associated fossil wood, precise provenance, and classic British Jurassic origin makes it both scientifically informative and visually striking. Multi-fossil blocks from the Jurassic Coast are increasingly scarce and highly sought after. Each specimen we offer is individually selected, ensuring you receive an authentic and carefully curated piece of Early Jurassic history from one of the world’s most important fossil localities.