Stephanoceras Ammonite Fossil Jurassic Inferior Oolite Dorset UK Genuine

Overview & Authenticity

Offered here is a genuine Stephanoceras ammonite fossil from the classic Inferior Oolite Formation of Burton Bradstock, Dorset, UK. This is a carefully chosen British Jurassic specimen, selected for preservation quality, strong shell detail, and overall display appeal. The photographs show the actual fossil you will receive, ensuring complete transparency and confidence when purchasing.
Every specimen is supplied with a Certificate of Authenticity, including a lifetime guarantee of genuineness, provided on a generic authenticity card.

This fossil was personally discovered by our own experienced team members Alister and Alison on 05 January 2024, and has been professionally cleaned, prepared, and treated by Alison, ensuring the fossil is fully stabilised and ready for long-term collection or display.

Geological Setting – Inferior Oolite, Dorset

The Inferior Oolite is a well-known Middle Jurassic limestone formation, deposited approximately 174–170 million years ago during the Bajocian Stage. At this time, southern England lay beneath a warm, shallow tropical sea rich in marine biodiversity.
The limestones and sandy oolitic sediments of the Inferior Oolite formed in high-energy carbonate shelf environments, where waves and currents created ideal conditions for the preservation of robust ammonite shells. Burton Bradstock is one of Dorset’s most important fossil localities, producing spectacular ammonites that have been collected and studied for generations.

Fossil Type & Scientific Classification

This specimen is an ammonite, an extinct marine cephalopod related to modern squid and cuttlefish. Stephanoceras is a classic Jurassic genus, widely recognised among collectors and palaeontologists.

• Order: Ammonitida

• Superfamily: Stephanoceratoidea

• Family: Stephanoceratidae

• Genus: Stephanoceras

Stephanoceras ammonites are important index fossils for the Middle Jurassic, helping define biostratigraphic zones within the Inferior Oolite.

Morphology & Notable Features

Stephanoceras is characterised by its strongly ribbed, planispirally coiled shell, with bold ornamentation and pronounced tubercles along the flanks and ventrolateral margins. Ribbing often bifurcates across the whorls, creating a highly textured and visually striking fossil.
This specimen retains clear three-dimensional form, allowing the shell sculpture to be appreciated in detail. Its natural limestone matrix provides excellent contrast, enhancing its display quality.

Depositional Environment & Fossilisation

During the Middle Jurassic, ammonites like Stephanoceras thrived as active nektonic predators in warm shallow seas. After death, their shells settled onto the carbonate seabed where rapid burial within oolitic sediments reduced damage and promoted fossil preservation.
Over millions of years, mineral replacement and lithification transformed the shell into stone while preserving the external ornamentation that makes ammonites so iconic.

Collecting & Display Value

British ammonites from Dorset are among the most desirable fossils in the world due to their provenance, scientific importance, and striking appearance. A Stephanoceras from Burton Bradstock represents a classic piece of the Jurassic Coast’s geological heritage.
Full sizing details are provided in the photographs. As a team-collected, expertly prepared specimen supplied with a Certificate of Authenticity and lifetime guarantee, this ammonite is ideal for collectors, educational use, museum-style display, or as a meaningful gift from deep geological time.