Promicroceras Calcite Ammonite Fossil with Impression Jurassic Coast Black Ven Dorset UK Lyme Regis

Description

Specimen Overview

This carefully selected fossil specimen features a Promicroceras calcite ammonite preserved alongside a natural ammonite impression, collected from the famous Black Ven Marls at Charmouth, near Lyme Regis, Dorset. The combination of a three-dimensional calcite-preserved shell with a clear impression in the surrounding matrix creates an informative and visually engaging piece that illustrates more than one mode of fossil preservation. The photographs show the exact specimen you will receive, with full sizing details provided in the images. As with all of our fossils, this piece is 100% genuine and comes complete with a Certificate of Authenticity.

Geological Formation and Locality

The fossil originates from Black Ven, one of the most productive and scientifically important fossil sites on the Jurassic Coast, a UNESCO World Heritage Site. The sediments here belong to the Lower Lias Group, deposited during the Early Jurassic, approximately 199–196 million years ago. The Black Ven Marls represent fine-grained marine muds laid down in a relatively calm offshore environment. These conditions allowed ammonite shells to be buried rapidly after death, protecting them from erosion and scavenging while enabling excellent preservation.

Fossil Type and Classification

Promicroceras is an extinct genus of ammonite belonging to the Class Cephalopoda, Subclass Ammonoidea, within the Order Ammonitida. Ammonites were free-swimming marine predators related to modern squid and cuttlefish and are among the most important index fossils used in Jurassic stratigraphy. Promicroceras is particularly characteristic of the earliest Jurassic ammonite faunas and is widely recognised for its stratigraphic and scientific significance within the Lower Lias.

Morphology and Preservation

The calcite-preserved Promicroceras displays the classic coiled shell form of the genus, with clearly defined whorls and visible growth features that record the animal’s development through life. Calcite replacement has enhanced surface detail while maintaining the original shell geometry. Adjacent to the shell, the ammonite impression preserves the outline and depth of the shell as it was embedded in the sediment, providing a complementary record of the original organism. Together, the shell and impression offer a valuable insight into the fossilisation process and the conditions of the Jurassic seabed.

Scientific and Collecting Significance

Ammonites from Charmouth and Lyme Regis have been collected and studied for over two centuries and played a key role in the development of early geological science. Promicroceras is particularly important for understanding Early Jurassic ammonite successions and marine ecosystems. Specimens from Black Ven are internationally recognised for their reliable provenance and scientific credibility. Fossils that preserve both a calcite shell and an impression are especially desirable, as they demonstrate multiple preservation pathways within a single piece.

Display, Care, and Authenticity

This fossil is well suited for display in a private collection, educational setting, or natural history cabinet, offering both aesthetic appeal and interpretive value. The specimen has been carefully cleaned to reveal its natural features, with no artificial restoration or reconstruction. You will receive the exact fossil shown in the photographs, accompanied by a Certificate of Authenticity, confirming its origin and genuine nature.

A scientifically informative and visually striking example from one of Britain’s most famous fossil localities, this Promicroceras ammonite with impression represents an authentic piece of Early Jurassic marine history from the Jurassic Coast.