Xipheroceras Calcite Ammonite Fossil Pebble Jurassic Coast Black Ven Charmouth Dorset UK

Description

Specimen Overview

Presented here is a genuine Xipheroceras calcite ammonite fossil pebble collected from the renowned Black Ven Marls at Charmouth, near Lyme Regis, Dorset. This carefully chosen specimen combines a naturally rounded pebble form with a clearly preserved ammonite, revealing the shell in calcite against the darker marl matrix. The result is a tactile, display-friendly fossil that remains entirely natural and unaltered by artificial shaping. The photographs show the exact specimen you will receive, with full sizing details clearly visible. As with all of our fossils, this piece is 100% genuine and supplied with a Certificate of Authenticity.

Geological Formation & Provenance

The fossil originates from Black Ven, one of the most important and productive fossil localities along the Jurassic Coast, a UNESCO World Heritage Site celebrated for its continuous exposure of Early Jurassic strata. The Black Ven Marls belong to the Lower Lias Group, deposited during the Early Jurassic Period, approximately 199–196 million years ago. These fine-grained marine mudstones were laid down in a relatively calm offshore environment, ideal for preserving ammonite shells. Subsequent coastal erosion naturally liberated and rounded some fossils into pebble forms, creating pieces such as this while retaining their geological integrity.

Fossil Type & Taxonomic Context

Xipheroceras is an extinct genus of ammonite within the Class Cephalopoda, Subclass Ammonoidea, and Order Ammonitida. Ammonites were free-swimming marine molluscs related to modern squid and cuttlefish and were among the most successful and diverse organisms in Jurassic seas. Xipheroceras is characteristic of Lower Lias ammonite assemblages and is valued for its distinctive shell form and stratigraphic importance within Early Jurassic marine successions.

Morphology & Calcite Preservation

This specimen preserves the recognisable coiled shell morphology of Xipheroceras, with whorl outlines visible through the calcite mineralisation. Calcite replacement has strengthened the fossil and enhanced contrast, allowing shell features to remain visible despite the naturally smoothed pebble exterior. The pebble form is the result of natural marine and coastal processes rather than artificial polishing, making this an authentic example of how fossils are weathered and revealed along the Dorset coastline.

Depositional Environment & Natural Formation

During the Early Jurassic, the area now forming Dorset lay beneath a warm, shallow sea rich in marine life. Ammonites such as Xipheroceras thrived in these waters, swimming actively in search of prey. After death, shells settled onto the seabed and were buried by fine muds. Over millions of years, these sediments compacted and mineralised into marl. Later erosion at Black Ven released some fossils, naturally rounding them into pebble forms while preserving the ammonite within.

Scientific & Collecting Significance

Ammonites from Black Ven, Charmouth, and Lyme Regis have been collected and studied for over two centuries and played a key role in the development of geological and stratigraphic science. Fossils from Black Ven are internationally recognised for their reliable provenance and scientific credibility. Pebble ammonites are particularly appealing to collectors as they combine geological authenticity with a naturally finished, handling-friendly form that highlights the processes shaping fossils along the Jurassic Coast.

Display, Care & Authenticity

This fossil is ideal for display in a private collection, educational setting, or natural history cabinet and is equally suited to close handling and examination. The specimen has been carefully cleaned to reveal natural features, with no artificial restoration or reconstruction applied. You will receive the exact fossil shown, accompanied by a Certificate of Authenticity, confirming its origin and genuine nature.

A classic and tactile ammonite from one of Britain’s most famous fossil cliffs, this Xipheroceras calcite ammonite fossil pebble from the Black Ven Marls represents an authentic piece of Early Jurassic marine history from the Jurassic Coast, Dorset, UK.