Xipheroceras Calcite Ammonite Fossil Jurassic Lyme Regis Dorset UK Lower Lias

Description

Authentic Xipheroceras Calcite Ammonite from the Jurassic Coast

Offered here is a genuine Xipheroceras calcite ammonite fossil collected from the classic Black Ven Marls at Stonebarrow Cliff, Charmouth, Lyme Regis, Dorset, part of England’s world-famous Jurassic Coast. This specimen has been carefully chosen for its preservation quality, clear morphology, and overall visual appeal. The photographs show the exact fossil you will receive, and full sizing details are shown in the photos to allow confident assessment prior to purchase.

This fossil is a genuine specimen and includes a Certificate of Authenticity lifetime guarantee generic card, ensuring long-term confidence in provenance and 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 consist of fine-grained marine mudstones and marls formed in a shallow epicontinental sea that once covered much of southern Britain. Stonebarrow Cliff is one of the most scientifically important Lower Jurassic exposures in Europe and is renowned for producing ammonites that underpin Jurassic biostratigraphy and palaeoenvironmental studies.

Fossil Type, Species, and Scientific Context

Xipheroceras is a distinctive Early Jurassic ammonite genus belonging to the Order Ammonitida, Superfamily Eoderoceratoidea, and Family Eoderoceratidae. It represents an important stage in early ammonite evolution following the end-Triassic extinction event. Xipheroceras is well documented from the Lower Lias of Dorset and is frequently referenced in scientific literature due to its characteristic shell form and stratigraphic significance.

Morphology and Calcite Preservation

This specimen displays the classic planispiral coiling typical of Xipheroceras, with relatively open whorls and pronounced ribbing across the flanks. Rib strength and spacing show natural variation through growth, providing insight into the ammonite’s ontogeny. The shell has undergone calcite mineralisation, which enhances fine surface detail and gives the fossil a pale, crystalline appearance that contrasts attractively with the darker marl matrix. Preservation quality allows the shell ornamentation and overall proportions to be clearly appreciated from multiple angles.

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 accumulated 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 of ammonites within the Black Ven Marls. These conditions are responsible for the exceptional fossil record preserved along the Jurassic Coast.

Collecting, Display, and Educational Value

This Xipheroceras calcite ammonite fossil is ideal for serious fossil collectors, educational collections, museum displays, or refined interior presentation. Its classic British Jurassic provenance, clear taxonomic identification, and strong visual presence make it both scientifically informative and aesthetically appealing. Ammonites from Stonebarrow Cliff are increasingly sought after due to their geological importance and consistent quality. Each specimen we offer is individually selected, ensuring you receive an authentic and carefully curated piece of Early Jurassic marine history from one of the world’s most important fossil coastlines.