RARE Calycoceras (Newboldiceras) hypocostatum Fossil Ammonite – Cenomanian, Cretaceous – Sarthe, France – Alice Purnell Collection

Description

For sale is an exceptional specimen of Calycoceras (Newboldiceras) hypocostatum, a fossil ammonite from the Cenomanian Stage of the Late Cretaceous, approximately 100 to 94 million years ago. This piece originates from the Sarthe region of France, a classic locality for marine Cretaceous invertebrates, and is part of the prestigious Alice Purnell Collection, known for its meticulously curated fossil material.

Calycoceras is a genus of ammonites in the family Acanthoceratidae, and Newboldiceras is considered a subgenus or morphotype. Calycoceras (Newboldiceras) hypocostatum is characterised by its ornamented, tuberculate shell and pronounced ribbing. These features made the animal highly adapted for a nektonic lifestyle in the warm, shallow epicontinental seas of the Cretaceous.

This fossil offers beautifully preserved detail, including visible shell sculpture and coiling, making it an excellent study specimen or collector’s piece.

Geological Context: The Cenomanian Stage is the earliest part of the Late Cretaceous, marked by rising sea levels and widespread marine transgressions across Europe. The Sarthe Department, located in northwestern France, provides access to fossiliferous chalk and limestone beds that yield ammonites, belemnites, echinoids, and bivalves. Ammonites from this area, like Calycoceras hypocostatum, are crucial for regional biostratigraphy and paleoenvironmental interpretation.

Key Details:

• Species: Calycoceras (Newboldiceras) hypocostatum
• Fossil Type: Extinct marine ammonite (cephalopod)
• Age: Cenomanian, Cretaceous (~100–94 million years ago)
• Location Found: Sarthe, France
• Provenance: From the Alice Purnell Collection
• Size: Please refer to the photo – scale rule / 1cm cube included for reference
• Condition: Excellent preservation with detailed ornamentation
• Authenticity: 100% genuine fossil, includes Certificate of Authenticity
• Photo: The exact specimen pictured is the one you will receive

Scientific & Collector Value: Calycoceras (Newboldiceras) hypocostatum is both scientifically valuable and highly collectible. Its striking morphology and rare occurrence in well-preserved condition make it a desirable fossil for academic reference, museum collections, or private display. The provenance from the Alice Purnell Collection adds significant pedigree.

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

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Add an exceptional Late Cretaceous ammonite to your collection with this rare Calycoceras (Newboldiceras) hypocostatum fossil from Sarthe, France.