Rare Fossil Ammonite Stephanoceras humphriesianum | Jurassic Middle Bajocian UK | Inferior Oolite Dorset | Genuine + COA

Description

This listing features a rare and striking fossil ammonite, Stephanoceras humphriesianum, discovered in the Inferior Oolite Formation, Middle Bajocian Stage of the Jurassic Period, from Burton Bradstock, Dorset, United Kingdom.

The fossil measures approximately 4–5 inches (see exact size via photo; scale cubes are 1cm). You will receive the exact specimen shown in the photographs, carefully selected for its preservation, detail, and scientific value.

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

Geological & Scientific Information:

• Fossil Type: Ammonite
• Species: Stephanoceras humphriesianum
• Order: Ammonitida
• Superfamily: Stephanoceratoidea
• Family: Stephanoceratidae
• Geological Stage: Middle Bajocian (~170.3 – 168.3 million years ago)
• Formation: Inferior Oolite
• Biozone: Humphriesianum Zone – serves as a key index zone within the Bajocian
• Depositional Environment: Shallow marine shelf, with carbonate sedimentation under moderately energetic conditions in the Wessex Basin
• Locality: Burton Bradstock, Dorset, England, UK

Morphology & Notable Features:

• Large, robust, and typically evolute shell structure
• Broad, well-developed ribs with bifurcation and tuberculate features
• Prominent keel and well-expressed suture lines
• The ribbing is often radial and dense, creating a visually impressive spiral pattern
• Excellent preservation provides valuable insight into Jurassic ammonite evolution

Scientific Significance:

Stephanoceras humphriesianum is an important biostratigraphic marker species within the Middle Jurassic, used across Europe for precise correlation of Bajocian strata. Its striking ribbed morphology and size make it both a desirable collector’s piece and a scientifically useful reference fossil.

The species was first described in classic 19th-century monographs and remains a staple ammonite genus in the stratigraphy of southern England.

Ideal For:

• Fossil collectors and paleontology enthusiasts
• Stratigraphic collections and reference materials
• Academic study or museum display
• Gift for geology or science fans

What You Will Receive:

• The exact fossil specimen of Stephanoceras humphriesianum as shown
• Certificate of Authenticity
• Secure packaging to ensure safe and protected delivery

Have questions? We’re always happy to assist! Whether you’re adding to a growing fossil collection or just beginning your journey into paleontology, this is a museum-grade ammonite that tells a story 170 million years in the making.