RARE 9″ Cunningtoniceras diadema Fossil Chalk Ammonite | Lower Cenomanian Cretaceous | Beachy Head Sussex UK | Alice Purnell Collection

Description

This listing showcases a RARE 9-inch Fossil Chalk Ammonite, scientifically identified as Cunningtoniceras diadema, from the Lower Cenomanian Stage of the Cretaceous Period. Collected at the iconic cliffs of Beachy Head, Sussex, UK, this exceptional specimen hails from the prestigious Alice Purnell Collection, celebrated for its high-grade and academically curated fossils.

Geological Details:

• Locality: Beachy Head, Sussex, United Kingdom
• Geological Period: Cretaceous
• Geological Stage: Lower Cenomanian (~100.5 to 98 million years ago)
• Depositional Environment: Quiet marine chalk sea rich in calcareous plankton; low-energy open shelf
• Formation: Lower Chalk (part of the Grey Chalk Subgroup of southern England)

Paleontological Context: Cunningtoniceras diadema is a large and ornate ammonite from the Acanthoceratidae Family, valued in biostratigraphy for defining early Cenomanian ammonite zones. This species is known for its strong shell ornamentation and tuberculate ridges, making it both scientifically important and visually striking.

• Order: Ammonitida
• Superfamily: Acanthoceratoidea
• Family: Acanthoceratidae
• Genus: Cunningtoniceras
• Species: diadema
• Biozone: Lower Cenomanian, associated with the Mantelliceras mantelli Zone
• Formally Described by: Seeley, 1865

Morphological Features:

• Robust, evolute shell with broad whorls
• Pronounced tubercles (spiny knobs) along rib intersections
• Sharp, radiating ribs typical of the genus
• Chalk preservation in pale white matrix with occasional calcite crystalisation
• Fine detail evident across the large shell surface

Notable Characteristics:

• Seldom-seen species from a world-famous fossil site
• Large 9″ specimen from a cliff locality with restricted access
• Traceable provenance from the Alice Purnell Collection
• High display and scientific value

Authenticity & Presentation:

• 100% genuine fossil, not a replica or reconstruction
• Supplied with an official Certificate of Authenticity
• Photo shows the exact specimen you will receive
• Scale cube = 1cm for accurate size reference (see image)

Additional Notes: This specimen is a rare opportunity to own a large, exquisitely preserved Cunningtoniceras diadema from the classic Beachy Head locality. With its bold ornamentation and historical provenance, it stands as a museum-grade piece perfect for serious collectors, institutions, or educational settings.

All of our Fossils are 100% Genuine Specimens & come with a Certificate of Authenticity.