RARE 5.75″ Uptonia jamesoni Fossil Ammonite – Lower Jurassic Pliensbachian, Charmouth UK – Authentic Display Specimen – COA Included

Description

This listing features a RARE 5.75″ Uptonia jamesoni fossil ammonite, a well-preserved and scientifically significant specimen from the Lower Pliensbachian Stage of the Early Jurassic Period, discovered in Charmouth, Dorset, United Kingdom. The photo shows the exact fossil specimen you will receive, professionally selected for its definition, completeness, and historical value.

Geological & Palaeontological Background:

• Species: Uptonia jamesoni (Sowerby, 1816)
• Fossil Type: Ammonite (extinct marine cephalopod)
• Geological Period: Jurassic
• Geological Stage: Lower Pliensbachian (~190–187 million years ago)
• Biozone: Jamesoni Zone – characteristic of this ammonite species
• Location: Charmouth, Dorset, UK

Uptonia jamesoni is a classic index fossil from the Lower Jurassic seas of Europe, especially well-known in the Dorset coastal exposures of the Blue Lias and Charmouth Mudstone Formations. It is considered an important biostratigraphic marker and is commonly used to define the Jamesoni Biozone, a major ammonite zone within the Lower Pliensbachian.

Morphology Features:

• Strongly ribbed, evolute shell with visible whorls
• Typically broad, rounded ribs with a prominent keel
• Ribbing continues uninterrupted across the venter (outer curve of the shell)
• Moderate to large size with open umbilicus and coiling

Depositional Environment: This specimen comes from the marine mudstone sequences deposited in the epicontinental seaway that covered much of Western Europe during the Early Jurassic. Calm, anoxic bottom waters contributed to the excellent preservation of ammonites and other marine fauna.

Taxonomic Classification:

• Family: Polymorphitidae
• Superfamily: Eoderoceratoidea
• Order: Ammonitida

Scientific Significance: Uptonia jamesoni was first described by James Sowerby in 1816, one of the pioneering figures in British palaeontology. Fossils from this genus have been extensively studied and serve as key biostratigraphic tools for dating marine sediments.

Additional Details:

• Certificate of Authenticity included: All our fossils are 100% genuine and accurately identified.
• Sizing: Approx. 5.75″ across. Please refer to the photo with Scale Rule Cube (each square = 1cm).
• A rare, display-quality ammonite, perfect for collectors, educators, or museum-quality showcases.

Add a remarkable piece of British palaeontological history to your collection with this stunning Uptonia jamesoni ammonite from the iconic Jurassic Coast of Charmouth.