RARE Thomelites sornayi British Chalk Ammonite Fossil – Cretaceous Shapwick Grange Devon UK – Certified Authentic

Description

RARE FOSSIL AMMONITE: THOMELITES SORNAYI

Presenting a rare and scientifically significant Thomelites sornayi ammonite fossil from the Cretaceous period, recovered from Shapwick Grange, Devon, United Kingdom. This specimen originates from the prestigious Alice Purnell Collection, ensuring both authenticity and expert selection.

What you see is exactly what you get — the listing photo shows the actual fossil specimen. A scale cube is provided (1cm per square) to help you gauge its true dimensions. Please refer to the photo for full sizing details.

This fossil is 100% genuine and comes with a Certificate of Authenticity.

Fossil Classification:

• Species: Thomelites sornayi
• Genus: Thomelites
• Family: Acanthoceratidae
• Superfamily: Acanthoceratoidea
• Order: Ammonitida
• Class: Cephalopoda
• Phylum: Mollusca
• Fossil Type: Ammonite (extinct marine mollusc)

Geological & Depositional Context:

• Geological Period: Cretaceous
• Likely Stage: Lower Cenomanian (exact stratigraphy at Shapwick Grange is not formally published but falls within Lower to Mid-Cretaceous chalk deposits)
• Formation: Chalk Group (British Chalk)
• Depositional Environment: Epicontinental marine shelf, characterised by low-energy, deep marine sedimentation of coccolith-rich limestone (chalk), formed in warm, shallow seas that covered large parts of present-day Europe during the Cretaceous.

Morphology & Notable Features:

Thomelites sornayi is recognised by its evolute coiling and smooth to weakly ornamented shell. While typically less robust than its cousin genera (such as Acanthoceras), it still displays key taxonomic features such as slight ribbing, weakly developed tubercles, and a planispiral form that appeals to both collectors and academic institutions.

This specific specimen displays excellent preservation detail with fine suture lines, and a matrix background that offers both visual contrast and natural presentation.

Biozone and Scientific Relevance:

While not the primary index fossil for Cenomanian biozonation, Thomelites sornayi is often used as a supplementary faunal guide in the correlation of British and European chalk deposits. Its presence helps refine the Lower Cenomanian faunal assemblages in SE and SW England.

Provenance & Collection Notes:

This fossil comes from the Alice Purnell Collection, renowned for its curated and locality-specific fossil specimens. Alice Purnell is a well-known figure in UK palaeontological circles, especially regarding field collection in the southwest regions of Britain.

Each fossil selected from this collection was carefully cleaned, conserved, and archived before release for sale.

Authenticity Guarantee:

• 100% genuine fossil
• Comes with a Certificate of Authenticity
• From the Alice Purnell Collection
• No restorations or replicas
• Ready for display or study

This rare fossil represents an exceptional piece of Earth’s history and would make a fine addition to any collection—whether educational, private, or museum-grade.