RARE Fossil Ammonite Macrocephalites rotundus – Lower Callovian, Jurassic – Blumberg, Germany – Certified – Alice Purnell Collection

Description

RARE FOSSIL AMMONITE – MACROCEPHALITES ROTUNDUS – LOWER CALLOVIAN, JURASSIC – BLUMBERG, GERMANY

This listing features a beautifully preserved and scientifically notable fossil ammonite: Macrocephalites rotundus, from the Lower Callovian stage of the Middle Jurassic, approximately 165–163 million years ago. This classic macrocephalitid specimen was discovered in the Blumberg region of Germany, renowned for its fine marine Jurassic exposures and fossil preservation.

From the renowned Alice Purnell Collection, this fossil is a carefully selected, authentic specimen. It is shown clearly in the photographs provided—what you see is exactly what you’ll receive. Scale rule cubes = 1cm. Please refer to the image for exact sizing. Comes complete with a Certificate of Authenticity confirming its genuine geological origin.

GEOLOGICAL & SCIENTIFIC DETAILS:

• Species: Macrocephalites rotundus
• Genus: Macrocephalites
• Geological Period: Middle Jurassic
• Stage: Lower Callovian
• Age Range: Approx. 165–163 million years ago
• Location Found: Blumberg, Baden-Württemberg, Germany
• Formation: Wutach Formation (Lower Callovian strata)
• Depositional Environment: Shallow marine shelf with fine-grained marl and limestone deposition
• Family: Macrocephalitidae
• Superfamily: Stephanoceratoidea
• Order: Ammonitida
• Phylum: Mollusca
• Class: Cephalopoda
• Biozone (likely): Macrocephalites gracilis Zone or Quenstedtoceras lamberti Zone (Lower Callovian)
• Formally Described by: (Likely attributed to Quenstedt or contemporary Jurassic specialists; specific identifier not documented here)

MORPHOLOGY & PALEONTOLOGICAL NOTES:

Macrocephalites rotundus is a characteristic ammonite with a broad, rounded whorl cross-section, a relatively evolute shell, and finely ribbed ornamentation. The genus Macrocephalites is important in Callovian biostratigraphy, serving as a reliable zone fossil across much of Europe.

This particular species, rotundus, is notable for its more inflated whorls and stronger ribbing compared to other species in the genus. Its preservation in the marine clays and marls of Blumberg makes it a textbook example of mid-Jurassic cephalopod fauna.

WHY THIS SPECIMEN IS SPECIAL:

• Authentic Macrocephalites rotundus from the Callovian of Germany
• Excellent preservation with visible suture lines and shell detail
• Represents an important index fossil for the Lower Callovian
• Part of the historic and respected Alice Purnell Collection
• Supplied with a Certificate of Authenticity
• A scientifically and visually appealing piece for collectors, educators, and enthusiasts

SUMMARY:

• Species: Macrocephalites rotundus
• Age: Lower Callovian, Middle Jurassic (~165–163 Ma)
• Locality: Blumberg, Germany
• Preservation: High-quality shell detail, natural matrix
• Provenance: Alice Purnell Collection
• Includes: Certificate of Authenticity
• Photographed With: 1cm scale cube for size reference

This ammonite fossil is a remarkable representation of Jurassic marine life and a stunning collectible backed by scientific heritage and authenticity.