Ilminster Ammonites

Introduction to Ilminster Ammonites

The area surrounding Ilminster in Somerset is famous for its Early Jurassic ammonites, many of which come from the Beacon Limestone Formation. Formerly known in part as the Junction Bed, this fossil-rich formation includes rocks dating from the latest Pliensbachian and Toarcian stages of the Jurassic Period.

Ammonites represented in our Ilminster collection commonly include Harpoceras and Hildoceras, alongside examples of Lytoceras, Haugia and Amaltheus. Identified species include Hildoceras bifrons, Hildoceras crassum, Hildoceras subplanatum, Lytoceras fimbriatum, Haugia variabilis, Amaltheus stokesi and Amaltheus gibbosus.

These ammonites are usually preserved as natural internal moulds within limestone. Many specimens are prepared, sectioned or polished to reveal their chambers and distinctive shell structures. Their varied forms make Ilminster ammonites both scientifically interesting and highly attractive British fossils for collectors.