Rare 14 Inch Paracoroniceras Ammonite Fossil Jurassic Lyme Regis Genuine Specimen with Premium Certificate of Authenticity

Description

Rare Large Paracoroniceras Ammonite from the Jurassic Coast

Offered here is an exceptional and rare 14-inch Paracoroniceras ammonite fossil from Monmouth Beach, Lyme Regis, Dorset, England. This is a genuine large-scale Jurassic ammonite, carefully chosen for its impressive size, strong morphology, and classic provenance from the world-famous Jurassic Coast. The photographs show the exact specimen you will receive, with full sizing clearly visible in the images.

This fossil is supplied with a fully hand-signed Premium Certificate of Authenticity, providing enhanced documentation and long-term confidence in its genuineness, provenance, and scientific importance.

Geological Context – Lower Lias, Semicostatum Zone

This ammonite originates from the Lower Lias Formation, dating to the Early Jurassic, approximately 199–190 million years ago. More specifically, it comes from the Semicostatum Zone, a well-defined ammonite biozone used internationally for stratigraphic correlation.

During the Early Jurassic, the Lyme Regis area lay beneath a warm, shallow epicontinental sea. Fine muds and limestones accumulated on the seabed, creating ideal conditions for preserving marine life. These sediments now form the iconic cliffs and beaches of the Dorset coast, recognised as a UNESCO World Heritage Site due to their geological significance.

Fossil Type and Species – Paracoroniceras

Paracoroniceras is a classic Early Jurassic ammonite genus belonging to the family Arietitidae within the order Ammonitida. These ammonites are characterised by their robust, evolute shells, strong ribbing, and pronounced keel, features that make them both scientifically important and visually striking.

Specimens of this size are uncommon, making this example particularly desirable. Large Paracoroniceras ammonites provide valuable insight into early Jurassic marine ecosystems and ammonite evolution following the end-Triassic extinction.

Morphology and Preservation

This specimen displays the defining features of Paracoroniceras, including broad whorls, strong radial ribbing, and a distinct keel running along the outer margin of the shell. The scale of the ammonite enhances these features, allowing the shell architecture and growth patterns to be clearly appreciated.

There has been some small restoration to the keel and centre, carried out sensitively to stabilise the fossil and improve overall presentation. This restoration is minor, does not detract from the specimen’s integrity, and is typical for large coastal ammonites recovered from dynamic shoreline environments. The fossil remains overwhelmingly original and authentic.

Depositional Environment and Paleoecology

Paracoroniceras lived as an active nektonic cephalopod, using jet propulsion to move through the Jurassic seas. It would have been a mid-level predator, feeding on smaller marine organisms while avoiding larger predators such as early marine reptiles.

The fine-grained marine sediments of the Lower Lias allowed rapid burial after death, protecting shells from extensive damage and enabling the exceptional preservation seen in specimens from Lyme Regis.

Scientific, Collecting, and Display Value

Ammonites from the Semicostatum Zone are important index fossils and are widely used in geological dating and stratigraphic studies. A specimen of this size and quality is highly sought after by serious collectors, museums, and advanced educational collections.

At 14 inches, this ammonite makes a commanding display piece, ideal for a focal point in a fossil cabinet, private collection, or professional setting. Its provenance from Monmouth Beach adds considerable historical and geological prestige.

The fossil shown is the exact specimen you will receive, ensuring complete transparency. Supplied with a fully hand-signed Premium Certificate of Authenticity, this rare Paracoroniceras ammonite represents a powerful and tangible link to life in the Early Jurassic seas and stands as an outstanding example of classic British paleontology.