Fossil Ammonite Kosmoceras jasoni Callovian Jurassic Wiltshire UK Genuine Specimen

Description

Authentic Jurassic Fossil Ammonite – Kosmoceras jasoni

This listing features a genuine Jurassic fossil ammonite, Kosmoceras jasoni, originating from the Callovian stage of the Middle Jurassic period and discovered in Wiltshire, United Kingdom. The fossil shown in the photographs is the exact specimen you will receive, displayed with a 1cm scale cube for accurate sizing. Every fossil comes with a Certificate of Authenticity, ensuring that your purchase is 100% genuine.

Geological Context – Callovian, Middle Jurassic

The Callovian stage, dating to approximately 166–163 million years ago, represents a period when shallow epicontinental seas covered much of present-day southern England. The Oxford Clay Formation and related deposits in Wiltshire are world-renowned for their rich fossil content, particularly ammonites, belemnites, marine reptiles, and bivalves. These clays and marls provided excellent preservation conditions, capturing the fine details of ammonite shells like this Kosmoceras jasoni.

Wiltshire’s fossil beds are part of a globally significant record of Middle Jurassic marine life. Fossils from these deposits are highly sought after by both private collectors and academic researchers.

Scientific Classification

• Kingdom: Animalia
• Phylum: Mollusca
• Class: Cephalopoda
• Order: Ammonitida
• Superfamily: Stephanoceratoidea
• Family: Kosmoceratidae
• Genus: Kosmoceras
• Species: Kosmoceras jasoni

This species is one of the classic ammonites used in biostratigraphy, as Kosmoceras jasoni defines the Jason Zone, a key biozone in the Callovian stratigraphy of Europe.

Morphology and Diagnostic Features

Kosmoceras jasoni is an ammonite highly prized for its distinct morphological traits, which include:

• Strong ribbing across the whorls, a defining feature of the genus.
• Tubercles (spiny nodes) positioned along rib intersections, giving the shell a textured, armored appearance.
• A moderately involute shell, with the inner whorls partly hidden by the outer ones.
• Complex suture patterns, typical of ammonites, visible where the chamber walls meet the shell.

These features not only make the ammonite visually striking but also serve as important taxonomic markers for paleontologists.

Palaeoecology and Lifestyle

Ammonites such as Kosmoceras jasoni were nektonic cephalopods, actively swimming in the open seas. They were predators and opportunistic feeders, using tentacles to capture small fish, crustaceans, and plankton. The ribbed and tuberculate shell provided both structural strength and hydrodynamic function, allowing the animal to maneuver effectively in Jurassic seas.

Their abundance in the fossil record, combined with their rapid evolutionary turnover, makes ammonites some of the most important index fossils for dating Jurassic marine sediments.

Collector and Display Significance

This Kosmoceras jasoni ammonite is not only scientifically important but also aesthetically appealing, making it an excellent choice for collectors. Fossils from the Jason Zone are highly desirable due to their role in stratigraphic dating and their distinctive morphology. This specimen represents a snapshot of marine life from over 160 million years ago, preserved in remarkable detail.

Whether you are a collector of Jurassic ammonites, a geology enthusiast, or someone seeking a unique natural history display piece, this fossil offers both scientific value and natural beauty.

Provenance and Guarantee

• Species: Kosmoceras jasoni
• Age: Jurassic, Callovian Stage (~166–163 million years ago)
• Locality: Wiltshire, United Kingdom

Every specimen is supplied with a Certificate of Authenticity, verifying its identity and guaranteeing it is a genuine fossil. The photographs show the actual ammonite you will receive.

This rare Jurassic ammonite, Kosmoceras jasoni, from Wiltshire, UK, combines scientific significance, geological history, and natural artistry, making it a valuable addition to any fossil collection.