Asteroceras Calcite Ammonite Fossil Jurassic Lyme Regis Dorset UK Lower Lias

Description

Authentic Asteroceras Calcite Ammonite from the Jurassic Coast

Offered here is a genuine Asteroceras calcite ammonite fossil with a cut base, collected from the renowned Black Ven Marls at Stonebarrow Cliff, Charmouth, Lyme Regis, Dorset, along England’s world-famous Jurassic Coast. This carefully chosen specimen combines natural preservation with a professionally cut base, allowing it to stand securely for display while retaining full fossil integrity. The photographs show the exact specimen you will receive, and full sizing details are clearly shown in the photos.

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

Geological Formation and Age

This ammonite 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 formed in a shallow epicontinental sea that once covered southern Britain. Stonebarrow Cliff is one of the most important Lower Jurassic localities in Europe, internationally recognised for producing abundant and well-preserved ammonites that are critical to Jurassic stratigraphy.

Fossil Type, Species, and Scientific Context

Asteroceras is a classic Early Jurassic ammonite genus belonging to the Order Ammonitida, Superfamily Eoderoceratoidea, and Family Eoderoceratidae. It is an important and easily recognisable ammonite within the Lower Lias and is frequently used in biostratigraphic studies of the Sinemurian. Specimens of Asteroceras from the Dorset coast are well documented in scientific literature and are highly regarded for their robust form and clear diagnostic features.

Morphology and Calcite Preservation

This specimen displays the distinctive planispiral coiling typical of Asteroceras, with broad whorls and strong, evenly spaced ribbing radiating across the flanks. The ribbing often terminates near the venter, giving the shell a bold and sculptural appearance. The ammonite has undergone calcite mineralisation, enhancing surface detail and providing a pale, crystalline finish that contrasts beautifully with the surrounding matrix. The cut base allows the fossil to be displayed upright, making it ideal for cabinets, shelves, or desks without the need for additional stands.

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. Fine sediments settled slowly on the sea floor, allowing ammonite shells to be rapidly buried after death. Periodic low-oxygen conditions reduced scavenging and disturbance, contributing to the excellent preservation seen in ammonites from the Black Ven Marls. These conditions underpin the global significance of the Jurassic Coast fossil record.

Collecting, Display, and Educational Value

This Asteroceras calcite ammonite fossil with cut base is ideal for serious fossil collectors, educational collections, museum displays, or refined interior presentation. Its classic British Jurassic provenance, well-defined morphology, and practical display preparation make it both scientifically informative and visually striking. Asteroceras ammonites from Stonebarrow Cliff are increasingly sought after, particularly well-prepared examples suitable for display. 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.