6.75″ Cut Polished Ammonite Fossil Matching Pair Cretaceous Madagascar A-Grade

Description

6.75″ Cut and Polished Ammonite Fossil Matching Pair – Genuine Cretaceous Specimen from Madagascar

This impressive 6.75″ cut and polished ammonite fossil matching pair is a stunning natural specimen originating from the Cretaceous strata of Madagascar. The ammonites have been expertly sliced and polished to reveal their intricate internal chamber patterns, mineral infill, and remarkable structural detail. The photographs show the exact pair you will receive, with 1 cm scale cubes included for accurate size reference. All of our Fossils are 100% Genuine Specimens and come with a Certificate of Authenticity.

Geological Origin and Age

These ammonite fossils come from the Cretaceous Period, a geological era spanning approximately 145 to 66 million years ago. Madagascar is world-renowned for its exceptionally preserved ammonite deposits, formed within marine sedimentary environments that once lay beneath warm, shallow Cretaceous seas. The region’s fossil-rich limestone and marl layers provide excellent conditions for the preservation of both external shell structure and internal suture patterns.

The polished interiors of these specimens reveal mineralised chambers often filled with calcite, aragonite, or other naturally occurring mineral deposits, formed as the original organic material was replaced during the fossilisation process.

Fossil Type, Species, and Classification

Fossil Type

• Ammonite (Subclass Ammonoidea) – an extinct group of marine cephalopods related to modern squids, cuttlefish, and nautilus.

Order and Superfamily

• Order: Ammonitida
• Superfamily: Often related to Desmoceratoidea or Hoplitoidea in Cretaceous Madagascan assemblages.

Morphological Features

These cut ammonites display features typical of Cretaceous ammonoids, including:

• Planispiral coiling with symmetrical whorls
• Distinct chamber divisions (septa) visible as curved internal lines
• Complex suture patterns indicative of advanced ammonite evolution
• Open, well-defined siphuncle pathways revealed in cross-section
• Mineral-filled chambers showing natural banding and crystallisation

The polished halves show the full internal structure, offering a unique view into the biological and geological processes that shaped their preservation.

Deposition and Environment

Ammonites from Madagascar lived in warm, shallow marine environments that supported diverse marine ecosystems during the Cretaceous Period. Upon death, their shells settled into soft seabed sediment, where low-oxygen conditions slowed decay and promoted the preservation of fine structural details.

Over millions of years, minerals replaced the original shell material, infilling chambers and strengthening the fossil. This mineralisation is visible in the polished halves, often showing calcite crystals, agate-like patterns, or natural colour variations.

Scientific and Collectable Significance

Ammonites play a crucial role in stratigraphy and biostratigraphic dating because their rapid evolutionary turnover and global distribution make them excellent index fossils. Madagascan Cretaceous ammonites frequently contribute to the identification of marine biozones used by palaeontologists to distinguish geological layers.

This pair offers a scientifically informative and aesthetically captivating view of ammonite anatomy, revealing:

• Septal folding and suture geometry
• Growth patterns and whorl expansion
• Internal chamber architecture

Such polished pairs are highly prized by collectors, educators, and enthusiasts for demonstrating both the beauty and biological complexity of these extinct marine cephalopods.

A-Grade Quality and Display Appeal

This ammonite pair has been carefully selected for its:

• High-quality polish
• Strong, visible chamber separation
• Clear suture patterns
• Balanced symmetry between the two halves
• Attractive mineral colours and natural crystallisation

Mounted together or displayed side-by-side, the pair forms a mirror-perfect presentation that highlights the fossil’s natural elegance and scientific interest. These specimens are ideal for interior décor, study collections, museum-style displays, or as a standout centrepiece for fossil enthusiasts.

Ideal for Collectors, Educators, and Natural History Enthusiasts

With its combination of geological history, palaeontological significance, and natural beauty, this 6.75″ cut and polished ammonite matching pair is a premium addition to any fossil collection. Carefully prepared and scientifically fascinating, it showcases millions of years of Earth’s ancient marine life preserved in exceptional detail.