VERY RARE: Algerites ellipticus Heteromorph Ammonite Fossil – Lower Cenomanian, Cretaceous – Glynde, UK – Alice Purnell Collection

Description

VERY RARE HETEROMORPH AMMONITE – ALGERITES ELLIPTICUS – LOWER CENOMANIAN, CRETACEOUS – GLYNDE, EAST SUSSEX, UNITED KINGDOM

This exceptional and very rare fossil specimen is of Algerites ellipticus, a heteromorph ammonite species dating back to the Lower Cenomanian stage of the Cretaceous period—approximately 100.5 to 98 million years ago. It was discovered in the Glynde area of East Sussex, an important locality within the British Chalk Formation known for its diverse ammonite fauna.

This fossil comes from the highly respected Alice Purnell Collection, offering both scientific integrity and careful specimen selection.

The image provided shows the actual specimen available. Please refer to the 1cm scale cube in the image for accurate sizing. All sizing and morphology are best assessed using the high-resolution photo provided.

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

FOSSIL & GEOLOGICAL DETAILS:

• Species: Algerites ellipticus
• Type: Heteromorph ammonite
• Geological Age: Lower Cenomanian, early Late Cretaceous (ca. 100.5–98 Ma)
• Location: Glynde, East Sussex, United Kingdom
• Formation: Lower Chalk / Grey Chalk Subgroup
• Depositional Environment: Open marine shelf, low-energy pelagic basin
• Family: Anisoceratidae
• Superfamily: Turrilitoidea
• Order: Ammonitida
• Class: Cephalopoda
• Phylum: Mollusca
• Collection: Alice Purnell
• Preservation: Well-defined heteromorph coiling, visible ribbing

MORPHOLOGICAL FEATURES & SCIENTIFIC CONTEXT:

Algerites ellipticus belongs to the heteromorph group of ammonites, characterised by non-planispiral shell coiling. This species exhibits a unique elliptical helical coiling with a relatively tight spiral in its early whorls that becomes more open with age. The surface often shows regular ribbing and nodes, indicative of its family Anisoceratidae.

This form is especially valuable to collectors and palaeontologists for understanding the morphological plasticity of ammonites during the Cenomanian transgression—when sea levels were high, and marine life diversified rapidly in newly formed epicontinental seas.

These ammonites are often associated with biozones defined by species such as Mantelliceras mantelli or Calycoceras naviculare within the British Chalk sequence, placing this fossil in a well-dated stratigraphic context.

WHY THIS SPECIMEN IS SPECIAL:

• Rare genus and species not commonly offered for sale
• Excellent preservation showing key heteromorph features
• Sourced from a significant UK chalk locality
• Part of the curated Alice Purnell Collection
• Includes a Certificate of Authenticity
• Educational and display-worthy specimen for collectors, educators, and institutions

SUMMARY:

• Fossil Type: Heteromorph Ammonite
• Species: Algerites ellipticus
• Age: Lower Cenomanian, Late Cretaceous
• Locality: Glynde, East Sussex, UK
• Geological Unit: Lower Chalk (Grey Chalk Subgroup)
• Collection: Alice Purnell
• Notable: Rare and scientifically valuable genus
• Coiling: Elliptical helical heteromorph
• Includes: Certificate of Authenticity
• Reference Cube: 1cm for scale in photo

This is a truly rare opportunity to own a scientifically important ammonite from the classic British Chalk fossil record.