Description
Kranosphinctes sp. — Large Natural Unpolished Ammonite | Jurassic | Madagascar
At 17 inches across and 8 inches thick, this specimen commands attention before you ever look at the detail. But it is the detail that makes it extraordinary.
This is a large, natural, unpolished Kranosphinctes sp. ammonite recovered from the Jurassic fossil beds of Madagascar — one of the world's most celebrated sources for ammonite material. The specimen has been left in its natural state, with no polishing, no artificial enhancement, and minimal repair. What you see is the fossil as the earth produced it over approximately 150 to 160 million years.
The specimen is complete through multiple whorls, from the tightly coiled inner umbilicus — rendered in warm amber and gold tones with fine, densely packed ribbing — outward through the progressively larger whorls of the mature body chamber. This nested whorl progression, visible in a single unobstructed view, is one of the most visually dramatic features a large ammonite can present. The outer shell retains its original cream and ivory calcite coloration, punctuated by natural brown matrix inclusions that speak to the specimen's geological authenticity. Strong radial ribs run across the venter throughout, characteristic of the Kranosphinctes form and exceptionally well-expressed on this example.Across its surface, the suture patterns are exceptionally well-preserved and clearly defined — the intricate, fern-like boundaries between the ammonite's internal chambers rendered in outstanding detail. Suture complexity of this quality is one of the primary markers collectors and institutions use to assess specimen grade, and this example delivers at the highest level.
Kranosphinctes is a perisphinctid ammonite genus known from Jurassic deposits across the Tethyan realm, with Madagascar's exposures producing some of the finest and largest examples on record. Specimens of this genus at this scale and preservation quality are genuinely uncommon in the private market.
Specimen Details:
- Species: Kranosphinctes sp.
- Classification: Ammonoidea — Perisphinctidae
- Age: Jurassic Period — approximately 150–163 million years ago
- Locality: Madagascar
- Condition: Excellent — minimal repair or restoration
- Suture Detail: Exceptional — clearly defined across specimen surface
- Finish: Natural unpolished
- Dimensions: 17" L × 14.5" W × 8" thick
- Weight: 61.6 lbs (28 kg)
- Display: Suitable for floor, shelf, or pedestal display at this scale
This is a centerpiece-grade specimen — the kind that defines a collection rather than simply adding to it. Appropriate for advanced private collectors, natural history institutions, interior design applications, and serious investors in natural history material.
