Apoderoceras Ammonite Fossil 5.5″ Rare Lyme Regis Dorset UK Lower Lias Jurassic Coast Belemnite Marls Large Display Specimen Authentic

Description

Rare 5.5″ Apoderoceras Ammonite – Jurassic Coast, Lyme Regis, Dorset

This outstanding 5.5-inch Apoderoceras ammonite fossil is a rare and impressive specimen from the Belemnite Marls Member of the Lower Lias, sourced from Stonebarrow on the Jurassic Coast, Lyme Regis, Dorset, UK. With its large size, strong preservation, and classic ammonite form, this specimen represents a highly desirable example of Early Jurassic marine life. The fossil shown in the photographs is the exact specimen you will receive, carefully selected for its quality and display appeal.

Geological Age & Formation

This ammonite dates to the Early Jurassic period, specifically the Sinemurian stage, approximately 190–199 million years ago. The Belemnite Marls Member is well known for its fossil-rich layers, deposited in a shallow marine environment where fine sediments allowed exceptional preservation. This horizon is particularly noted for abundant ammonites and belemnites, making it a key stratigraphic unit within the Lower Lias of Dorset.

Taxonomy & Classification

• Order: Ammonitida
• Superfamily: Psiloceratoidea
• Family: Polymorphitidae
• Genus: Apoderoceras

Apoderoceras is a distinctive Lower Jurassic ammonite genus, often associated with early evolutionary diversification following the end-Triassic extinction. It is valued by collectors for both its rarity and its elegant shell form.

Morphology & Notable Features

This specimen displays the classic planispiral coiling typical of ammonites, with well-defined whorls and pronounced ribbing. Apoderoceras is recognised for its moderately involute shell and strong, often bifurcating ribs that extend across the flanks, creating a textured and dynamic surface. The ribs may show subtle variations in strength and spacing, adding to the visual interest of the fossil.

The size of this specimen at 5.5 inches makes it particularly impressive, as larger examples are less commonly encountered. Its proportions and preservation highlight the natural symmetry and growth patterns of this extinct cephalopod.

Depositional Environment

The Belemnite Marls represent a marine depositional setting where sediments accumulated in relatively calm waters. Periodic changes in oxygen levels on the seabed contributed to excellent fossil preservation, allowing ammonites like Apoderoceras to retain fine morphological details. These seas were home to a diverse ecosystem including ammonites, belemnites, bivalves, and marine reptiles.

Discovery & Expert Preparation

This fossil was discovered by our experienced team members, Alister and Alison, along the Dorset coastline. After careful extraction, the specimen was professionally cleaned, stabilised, and prepared by Alison to enhance its natural features while preserving its integrity. The preparation ensures that the fossil is both structurally sound and visually striking.

Authenticity & Provenance

This is a genuine Apoderoceras ammonite fossil and includes a fully hand-signed Premium Certificate of Authenticity. All specimens are responsibly sourced and expertly prepared, providing complete confidence in both authenticity and provenance.

Display & Collectability

Large Apoderoceras ammonites from Lyme Regis are highly sought after due to their rarity, size, and historical significance. This specimen is ideal for serious collectors, educational collections, or as a standout display piece. Its origin from the Jurassic Coast, a UNESCO World Heritage Site, further enhances its desirability.

Condition & Sizing

The ammonite measures approximately 5.5 inches across. Please refer to the photographs for full sizing and condition details, as they form part of the description and accurately represent the exact specimen you will receive.