Rare Platypleuroceras brevispina Ammonite Fossil Genuine Jurassic Upper Pliensbachian St Peters Field Radstock UK with COA

Description

100% Genuine Rare Platypleuroceras brevispina Ammonite Fossil

Presented here is a rare Platypleuroceras brevispina ammonite fossil from the Upper Pliensbachian stage of the Jurassic period, discovered at St Peters Field, Radstock, Somerset, United Kingdom. The fossil shown in the photographs is the exact specimen you will receive, with a 1cm scale cube for accurate size comparison. All of our fossils are 100% genuine specimens, each accompanied by a Certificate of Authenticity for complete assurance of provenance.

Geological Background – Upper Pliensbachian, Jurassic

This ammonite dates back to the Upper Pliensbachian stage of the Early Jurassic, around 185 million years ago. During this time, much of Britain was submerged beneath shallow marine environments, where fine sediments accumulated in the Lower Lias Group. These calm, epicontinental seas provided ideal conditions for ammonite preservation, giving rise to some of the most important fossiliferous deposits in Europe.

The St Peters Field site in Radstock is a significant fossil locality, particularly renowned for ammonites from the Spinatum Zone. This biozone is internationally recognised and used in stratigraphic correlation of Early Jurassic rocks across Europe. Ammonites found here are not only highly collectable but also scientifically valuable for refining the geological timescale.

Fossil Type and Species – Platypleuroceras brevispina

Platypleuroceras brevispina is an extinct ammonite species belonging to the order Ammonitida, superfamily Eoderoceratoidea, and family Pleuroceratidae. This genus is especially distinctive for its ornate shell structure and spined ornamentation. Specimens are comparatively rare in British deposits, making them highly prized among fossil enthusiasts.

Ammonites of this type were nektonic predators, actively swimming in open waters and preying on smaller marine organisms. Their complex shell structure allowed them to regulate buoyancy and manoeuvre effectively in Jurassic seas.

Morphology and Distinguishing Features

The shell of Platypleuroceras brevispina is evolute, with whorls that are not tightly coiled, leaving earlier whorls visible. It is characterised by strong, sharp ribbing across the flanks that often terminate in short spines or tubercles along the ventrolateral shoulders. These spines are the basis of the species name “brevispina,” meaning “short-spined.”

Ribbing is typically bifurcating, producing a striking sculptured appearance. The venter (outer whorl edge) is well defined, with the ribs continuing across it, giving the ammonite a robust yet elegant form. The suture lines are highly complex, featuring lobes and saddles that add further detail to its morphology.

Biozone and Scientific Importance

Platypleuroceras brevispina is a key species within the Spinatum Zone of the Upper Pliensbachian, serving as an important marker for Jurassic biostratigraphy. Its restricted stratigraphic range makes it a reliable index fossil, helping geologists to correlate layers of the same age across different regions.

This particular species also reflects evolutionary adaptations of ammonites during a dynamic interval in Early Jurassic history, where diversity and morphological experimentation were at their peak. Specimens like this one therefore hold both aesthetic appeal and significant scientific relevance.

Collectors and Enthusiasts

For collectors, a Platypleuroceras brevispina ammonite fossil represents an extraordinary acquisition. Its rarity, ornate ribbing, and spined morphology distinguish it from more common ammonite forms. Combined with its provenance from Radstock’s St Peters Field, this specimen is highly desirable for both private collections and educational displays.

Why This Specimen is Unique

• Rare Platypleuroceras brevispina ammonite fossil
• From the Upper Pliensbachian, Spinatum Zone (~185 million years old)
• Discovered at St Peters Field, Radstock, United Kingdom
• Distinctive ribbing and spined morphology
• Belongs to the family Pleuroceratidae, order Ammonitida
• Supplied with a Certificate of Authenticity
• Exact specimen shown in the photographs will be sent
• 1cm cube included for precise scale reference

This rare Platypleuroceras brevispina ammonite fossil from Radstock is an outstanding and scientifically significant specimen. Its ribbing, spined features, and well-documented provenance make it a remarkable addition to any collection of Jurassic ammonites.