Rare 6.75″ Fossil Ammonite Pictonia baylei, Lower Kimmeridgian, Jurassic, Swindon UK, Genuine with COA

Description

Available here is a Rare 6.75″ Fossil Ammonite of Pictonia baylei from the Lower Kimmeridgian Stage of the Late Jurassic, discovered in the renowned fossiliferous layers of Lidyard Field, near Swindon, United Kingdom. This large, robust ammonite is an outstanding example of a classic Upper Jurassic faunal group, prized by collectors and researchers alike.

The specimen in the photographs is the actual fossil you will receive. It has been carefully selected for quality, scientific relevance, and display appeal.

Scale Rule Squares / Cube = 1cm — refer to the image for accurate size reference.

Geological & Taxonomic Details:

• Species: Pictonia baylei
• Fossil Type: Ammonite (extinct marine mollusc)
• Geological Period: Jurassic
• Geological Stage: Lower Kimmeridgian (Upper Jurassic)
• Approximate Age: ~157 to 155 million years ago
• Location: Lidyard Field, Swindon, Wiltshire, England, UK
• Formation: Likely from the Kimmeridge Clay Formation
• Order: Ammonitida
• Superfamily: Perisphinctoidea
• Family: Aulacostephanidae
• Described By: E. Oppel, 1863

Morphology Features:

Pictonia baylei is part of the Aulacostephanid ammonites, easily recognisable by its evolute shell, strong ribbing, and broad, flattened whorls. The ribs typically bifurcate (split) near the midpoint of each whorl and sweep gently toward the venter (outer margin), which is typically rounded to slightly keeled. The whorl section is compressed with a prominent umbilicus, and ornamentation is strong — this specimen beautifully illustrates these classic Jurassic features.

Biozone & Stratigraphy:

Pictonia baylei is the index fossil for the Baylei Zone, a key subdivision of the Lower Kimmeridgian. As such, it is of significant importance in biostratigraphy and is widely used for correlating marine strata across the United Kingdom and northwest Europe.

Depositional Environment:

This ammonite was preserved in sediments laid down in a relatively deep, offshore marine basin. The Kimmeridge Clay Formation, known for its dark shales and claystones, represents a low-energy depositional setting with occasional anoxic conditions, ideal for the preservation of marine fossils.

Scientific Importance:

As a zone fossil, Pictonia baylei plays a crucial role in the chronostratigraphic subdivision of the Jurassic System. Its wide distribution and short vertical range make it extremely useful for geologists and palaeontologists studying the evolution, migration, and extinction patterns of ammonite faunas during the Late Jurassic.

Authenticity & Guarantee:

All of our fossils are 100% genuine, responsibly collected, and professionally prepared. Each specimen is supplied with a Certificate of Authenticity, ensuring provenance and confidence in your purchase.

This Pictonia baylei fossil is a rare and scientifically valuable ammonite with excellent preservation and a striking appearance. Whether you’re a collector, educator, or enthusiast, it is a superb display piece and reference example from the Kimmeridgian of the UK.

Let us know if you would like additional labelling, packaging, or information for educational or display purposes.