Rare Subdichotomoceras websteri Fossil Ammonite – Upper Kimmeridgian, Upper Jurassic, Kimmeridge Bay Dorset UK – Genuine + COA

Description

A rare Subdichotomoceras websteri Fossil Ammonite, from the Upper Kimmeridgian Stage of the Upper Jurassic, collected at Kimmeridge Bay, Dorset, United Kingdom. This specimen is an excellent representative of the genus Subdichotomoceras, notable for its distinctive ribbing and importance in Jurassic stratigraphy. The fossil pictured is the exact specimen you will receive, supplied with a Certificate of Authenticity.

Fossil Type & Species:

• Type: Ammonite (extinct marine cephalopod)
• Species: Subdichotomoceras websteri
• Order: Ammonitida
• Superfamily: Perisphinctoidea
• Family: Aulacostephanidae

Geological Context:

• Period: Jurassic
• Epoch/Stage: Upper Jurassic – Upper Kimmeridgian (approx. 155 to 152 million years ago)
• Biozone: Commonly associated with the Baylei Zone and Pectinatus Zone, important ammonite horizons of the Upper Kimmeridgian
• Formation: Kimmeridge Clay Formation
• Depositional Environment: Marine shelf dominated by organic-rich clays and shales, excellent for fossil preservation

Locality:

• Region: Kimmeridge Bay, Dorset, United Kingdom

Morphology & Features:

• Evolute shell with moderately wide umbilicus
• Coarse, bifurcating ribs extending across the flanks and over the venter
• Strong ornamentation diagnostic of Subdichotomoceras websteri
• Excellent preservation with detailed ribbing visible

Scientific Notes:

• Subdichotomoceras websteri was first described in the 19th century as part of classic studies on British Jurassic ammonites
• The genus Subdichotomoceras is a key taxon in Upper Kimmeridgian ammonite biostratigraphy, widely used in NW Europe

Notable Details:

• Rare British ammonite from the world-famous Kimmeridge Bay locality
• Excellent preservation of ribbing and shell detail
• 100% genuine, natural fossil – no restoration
• Scale Reference: Each square or cube in the photo = 1cm. Please see photographs for accurate sizing

Authenticity & Guarantee: All of our fossils are 100% genuine, responsibly sourced, and professionally curated. Every purchase includes a Certificate of Authenticity. The fossil shown is the exact specimen you will receive.

This Subdichotomoceras websteri ammonite is a rare and scientifically valuable fossil from the Upper Kimmeridgian of Dorset – an outstanding addition for collectors, researchers, or natural history displays.