Asteroceras Ammonite Fossil 3″ Calcite Jurassic Lyme Regis Dorset UK Black Ven Marls Lower Lias Rare Display Specimen Authentic

Description

Asteroceras Calcite Ammonite Fossil – Jurassic Coast, Dorset, UK

This exceptional 3-inch Asteroceras ammonite fossil originates from the world-famous Black Ven Marls of the Lower Lias on the Jurassic Coast at Stonebarrow Cliff, Charmouth, near Lyme Regis, Dorset, UK. A beautifully preserved specimen, this fossil displays striking calcite mineralisation, enhancing both its visual appeal and collectability. The exact specimen shown in the photographs is the one you will receive, carefully selected for its quality and presentation.

Geological Context & Age

This ammonite dates to the Early Jurassic period, specifically the Sinemurian stage, approximately 190–199 million years ago. The Black Ven Marls are renowned for yielding some of the finest marine fossils in the UK, formed in a calm, shallow sea environment rich in life. Asteroceras is commonly associated with the Asteroceras obtusum Biozone, an important stratigraphic marker used by palaeontologists to date Lower Jurassic sediments with precision.

Taxonomy & Classification

• Order: Ammonitida
• Superfamily: Psiloceratoidea
• Family: Asteroceratidae
• Genus: Asteroceras

Asteroceras is a classic Lower Jurassic ammonite genus, widely recognised for its evolutionary importance and distinctive morphology.

Morphology & Notable Features

This specimen exhibits the characteristic planispiral coiling typical of ammonites, with strong, ribbed ornamentation radiating across the shell. The ribs often bifurcate and create a textured, dynamic surface, while the whorls are moderately inflated, giving the fossil a robust and well-defined profile. The calcite preservation adds a subtle crystalline shimmer, enhancing the natural beauty of the fossil and making it an outstanding display piece.

Depositional Environment

The Black Ven Marls represent a marine depositional environment, where fine sediments settled in relatively low-energy conditions. This allowed for exceptional fossil preservation, often retaining intricate shell details. The presence of ammonites like Asteroceras indicates a thriving open marine ecosystem, rich in cephalopods and other marine organisms.

Discovery & Preparation

This fossil was discovered by our experienced team members, Alister and Alison, along the Dorset coastline. Following its discovery, it was expertly cleaned, prepared, and stabilised by Alison to ensure both its longevity and visual appeal. Every step of the preparation process has been carried out with care to preserve the fossil’s natural integrity.

Authenticity & Provenance

This is a 100% genuine fossil specimen and comes complete with a fully hand-signed Premium Certificate of Authenticity. All of our fossils are ethically sourced and responsibly prepared, ensuring you receive a piece of natural history with verified provenance.

Display & Collectability

With its classic ammonite form, attractive calcite finish, and well-defined ribbing, this Asteroceras specimen is ideal for collectors, educators, or anyone with an appreciation for prehistoric life. Its manageable size makes it perfect for display in a cabinet, office, or study, while its scientific significance adds depth to any fossil collection.

Condition & Sizing

The fossil measures approximately 3 inches across. Please refer to the provided photographs for full sizing and condition details, as they form part of the description and accurately represent the specimen you will receive.