Rare Fossil Ammonite Homeoplanulites difficilis | Jurassic Lower Callovian Yorkshire UK | Genuine + COA

Description

This listing features a rare and well-preserved fossil ammonite, Homeoplanulites difficilis, from the Lower Callovian Stage of the Jurassic Period, found in South Cave Quarry, Yorkshire, United Kingdom. The photo shows the exact fossil specimen you will receive. Each cube in the image represents 1cm — please refer to the photo for full sizing.

This is a scientifically significant and display-worthy ammonite, ideal for serious collectors, paleontologists, or academic display.

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

Geological & Scientific Information:

• Fossil Type: Ammonite
• Species: Homeoplanulites difficilis
• Order: Ammonitida
• Superfamily: Perisphinctoidea
• Family: Kosmoceratidae
• Geological Stage: Lower Callovian (approx. 166.1 – 164.7 million years ago)
• Biozone: Possibly associated with the Macrocephalites or Bullatimorphites Zones
• Formation: Oxford Clay Group / Lower Callovian deposits
• Period: Jurassic
• Locality: South Cave Quarry, East Yorkshire, England, UK
• Depositional Environment: Offshore marine basin with low-energy conditions; clay-rich and finely laminated sediments

Morphology & Notable Features:

• Evolute, planispiral coiling with a wide umbilicus
• Finely ribbed shell with consistent and evenly spaced ornamentation
• Flanks slightly flattened; ribs may bifurcate
• Smooth or subtly keeled venter depending on preservation
• A characteristic species showing transitional traits within Kosmoceratidae evolution

Scientific Significance:

Homeoplanulites difficilis is a key ammonite species for interpreting Lower Callovian biostratigraphy in Britain and Europe. Though rarely offered on the market, it contributes greatly to our understanding of ammonite diversification within the Kosmoceratidae family and offers insight into mid-Jurassic marine ecosystems.

It is occasionally referenced in historic European Jurassic monographs and remains a significant regional biostratigraphic fossil.

Ideal For:

• Fossil collectors and ammonite specialists
• Academic and biostratigraphic study
• Museum-quality or display-focused collections

What You Will Receive:

• The exact Homeoplanulites difficilis fossil shown in the images
• Certificate of Authenticity
• Secure and professional packaging for safe delivery

If you have any questions, feel free to reach out. We’re always happy to help you expand your fossil collection or provide more detailed geological context.