RARE Fossil Ammonite Quenstedtoceras lamberti cadiforme – Upper Callovian, Jurassic – Switzerland – Certified – Alice Purnell Collection

Description

RARE FOSSIL AMMONITE – Quenstedtoceras lamberti cadiforme

Upper Callovian Stage | Jurassic Period

SWITZERLAND

This listing showcases a striking and scientifically significant specimen of Quenstedtoceras lamberti cadiforme, a member of the ammonite family Cardioceratidae, from the Upper Callovian Stage of the Jurassic Period, approximately 161–159 million years ago.

This well-preserved ammonite was collected in Switzerland and is a rare and diagnostic form of Quenstedtoceras, known for its role as a key index fossil within Upper Jurassic European marine sequences.

This particular fossil comes from the Alice Purnell Collection and is accompanied by a Certificate of Authenticity. The specimen in the photo is the exact one you will receive. A 1cm scale cube is visible in the images for accurate sizing – please refer to the listing photos for full dimensions.

GEOLOGICAL & TAXONOMIC DETAILS:

• Species: Quenstedtoceras lamberti cadiforme
• Geological Period: Jurassic
• Stage: Upper Callovian (~161–159 Ma)
• Location: Switzerland
• Depositional Environment: Shallow marine epicontinental sea; well-oxygenated shelf setting with fine sediment accumulation
• Biozone: Typically linked to the lamberti Zone of the Upper Callovian – a key marker in regional stratigraphy
• Order: Ammonitida
• Superfamily: Stephanoceratoidea
• Family: Cardioceratidae
• Class: Cephalopoda
• Phylum: Mollusca

MORPHOLOGY FEATURES:

This subspecies, Q. lamberti cadiforme, is noted for:

• Evolute shell structure with visible inner whorls
• Fine ribbing with strong primary ribs and secondaries that bifurcate or trifurcate from the umbilical shoulder
• Compressed cross-section, giving it a disc-like appearance
• A distinct ventral keel, common in Quenstedtoceras-type ammonites
• Often used as a biozonation tool for defining the uppermost Callovian strata across Europe

PALEONTOLOGICAL SIGNIFICANCE:

Quenstedtoceras lamberti cadiforme is an important ammonite for biostratigraphy in Western and Central Europe. Its distribution in upper Callovian sequences makes it valuable for correlating strata across the Paris Basin, Swiss Jura, and parts of the North Sea Basin. These ammonites are associated with transgressive-regressive cycles, often found in marly or calcareous siltstones indicative of stable, offshore marine platforms.

SPECIMEN SUMMARY:

• Species: Quenstedtoceras lamberti cadiforme
• Age: Upper Callovian, Jurassic (~161–159 Ma)
• Location: Switzerland
• Biozone: lamberti Zone
• Preservation: Excellent – visible ribbing, diagnostic features intact
• Authenticity: Certificate of Authenticity included
• Collection: Alice Purnell
• Scale Reference: 1cm cube in photos – full measurements provided in listing

This is a highly collectible ammonite, ideal for specialists in Jurassic paleontology, stratigraphic collectors, or anyone seeking a distinctive and certified piece from one of Europe’s most geologically rich Jurassic regions.