Hildoceras Fossil Ammonite in Matrix from Beacon Limestone Jurassic Ilminster Somerset UK

Description

Hildoceras Fossil Ammonite – Beacon Limestone, Jurassic, Ilminster, Somerset, UK

This beautiful Hildoceras Fossil Ammonite in Matrix is an authentic specimen from the Beacon Limestone Formation, collected from the classic fossil-bearing beds near Ilminster, Somerset, UK. It dates to the Lower Jurassic Period (Toarcian Stage, approximately 182–174 million years ago). The fossil was discovered by our own team members, Alister and Alison, on the 22nd of October 2025, and has been carefully cleaned, prepped, and treated by Alison to reveal its exquisite natural detail while preserving its geological integrity. The scale cube equals 1cm, and the photograph shows the actual specimen you will receive.

This remarkable ammonite offers an exceptional opportunity to own a piece of Britain’s rich Jurassic heritage, beautifully preserved within its original limestone matrix — a perfect blend of natural artistry and ancient science.

Scientific Classification and Geological Context

• Genus: Hildoceras
• Family: Hildoceratidae
• Superfamily: Hildoceratoidea
• Order: Ammonitida
• Geological Stage: Toarcian (Lower Jurassic)
• Formation: Beacon Limestone
• Locality: Ilminster, Somerset, England

Hildoceras is a genus of ammonite characterised by its strongly ribbed, tightly coiled, and laterally compressed shell, often displaying a beautiful spiral symmetry. These ammonites are iconic fossils of the Lower Toarcian age, frequently found in association with fine-grained marine limestones formed in the shallow tropical seas that once covered much of southern England.

The Beacon Limestone Formation represents a depositional environment of calm, oxygen-rich marine waters, where fine carbonate muds slowly accumulated, preserving an abundance of marine life. The area around Ilminster is particularly famous for yielding complete and well-preserved ammonites, crinoid fragments, and other marine fossils from this time.

Morphology and Distinguishing Features

This Hildoceras specimen exhibits all the hallmark traits of the genus, including:

• A tightly coiled planispiral shell with a compressed whorl section.
• Prominent, gently curved ribs radiating from the umbilicus to the outer venter.
• A smooth, rounded outer keel typical of the Hildoceratidae family.
• Fine preservation of chambered septa, visible within the limestone matrix.

The matrix surrounding the fossil provides a beautiful natural frame, enhancing the aesthetic contrast between the pale limestone and the darker fossil material. When viewed closely, the subtle details of the shell’s ribbing and curvature showcase the intricate structure and beauty of this ancient marine cephalopod.

Palaeontological Significance

Ammonites such as Hildoceras were fast-swimming marine molluscs related to modern squids and octopuses. Their coiled shells were divided into gas-filled chambers that provided buoyancy and stability, allowing them to move efficiently through Jurassic seas.

Hildoceras is an important index fossil, helping geologists to date and correlate rock layers across different regions. Its presence marks the Hildoceras bifrons Biozone, a key interval in the Lower Toarcian stratigraphy of Europe. Fossils from this genus provide valuable insight into the evolutionary development of ammonites and the changing marine environments of the Jurassic world.

The Toarcian stage also represents a significant time in Earth’s geological history, associated with major environmental changes including oceanic anoxic events, which influenced the distribution and preservation of marine organisms. Specimens like this one capture a moment frozen in stone from nearly 180 million years ago.

Discovery and Preparation

This particular ammonite was discovered by Alister and Alison on 22 October 2025 during one of our field expeditions to the classic fossil sites near Ilminster. It was subsequently cleaned, prepared, and treated by Alison, whose meticulous conservation work ensured that the fossil’s natural beauty was preserved while stabilising its structure. The result is a specimen that highlights both its scientific significance and aesthetic appeal.

Authenticity and Presentation

All of our fossils are 100% genuine specimens and are supplied with a Certificate of Authenticity confirming their provenance, geological formation, and identification. The scale cube equals 1cm, and the photo displays the exact fossil you will receive. The specimen has been professionally conserved to protect its surface detail and ensure its longevity for generations to come.

A Rare and Beautiful British Jurassic Fossil

Owning a Hildoceras Fossil Ammonite from the Beacon Limestone is like holding a tangible piece of Earth’s ancient ocean history. Its timeless spiral form, preserved for millions of years in Somerset’s Jurassic limestone, embodies the story of life’s evolution in prehistoric seas. Whether you are a fossil collector, geology enthusiast, or admirer of natural beauty, this genuine Hildoceras ammonite is a truly exceptional specimen — scientifically significant, beautifully prepared, and steeped in geological heritage.