Rare Eubostrychoceras indopacificum Heteromorph Ammonite Fossil Coniacian Cretaceous Madagascar

Description

This listing is for a rare Eubostrychoceras indopacificum heteromorph ammonite fossil, dating from the Coniacian stage of the Late Cretaceous Period, approximately 89–86 million years old. Sourced from the world-renowned fossil beds of Madagascar, this specimen represents one of the most unusual and visually striking ammonites, belonging to the heteromorph group known for their irregular and uncoiled shell structures. Its rarity and distinctive morphology make it a superb specimen for both collectors and researchers.

All of our fossils are 100% genuine specimens and supplied with a Certificate of Authenticity. The photographs show the exact specimen you will receive, with a 1 cm scale cube and rule squares provided for accurate size reference. Please consult the photos for precise measurements.

Geological Context and Age

This ammonite originates from the Coniacian stage of the Late Cretaceous, a period characterised by high global sea levels and extensive shallow marine habitats. Madagascar, positioned in the southern Tethys Ocean during this time, was home to a diverse array of marine organisms including ammonites, belemnites, marine reptiles, and early fish.

The marine sediments of Madagascar are globally renowned for producing exceptionally preserved ammonites. Specimens like Eubostrychoceras indopacificum provide crucial insights into the diversity of heteromorph ammonites and their distribution across the Tethyan realm. Their presence helps refine stratigraphic zones and contributes to our understanding of Coniacian biozones.

Morphology and Distinctive Features

Eubostrychoceras indopacificum is a member of the family Nostoceratidae, within the superfamily Turrilitoidea of the order Ammonitida. This group is characterised by heteromorphic shell forms, which deviate from the tightly coiled spirals of typical ammonites. Instead, Eubostrychoceras exhibits a helically wound, loosely coiled, or irregularly curved shell, often forming tower-like spirals.

This specimen demonstrates the helically twisted and irregular coiling that defines the genus. The shell also displays ribbing and ornamentation along its surface, enhancing its distinct appearance. The unusual morphology of heteromorph ammonites has led palaeontologists to suggest that they occupied unique ecological niches, perhaps drifting or hovering in the water column rather than swimming actively like their planispiral relatives.

Scientific Importance

Heteromorph ammonites such as Eubostrychoceras indopacificum are of considerable scientific importance because they showcase evolutionary experimentation within the ammonite lineage. Their distinctive shell shapes represent adaptive strategies that differ from the streamlined coiling of most ammonites. These fossils also serve as excellent index fossils, enabling geologists to identify and date specific marine strata within the Coniacian stage.

The study of Eubostrychoceras helps palaeontologists better understand the palaeoecology of Late Cretaceous seas and the diversity of ammonite morphologies. Madagascar’s well-preserved examples play an important role in documenting the global distribution of this unusual ammonite genus.

Collector and Display Value

This rare heteromorph ammonite fossil is a highly desirable piece for collectors due to its unusual form, rarity, and provenance. Its elegant, spiral-like coiling and robust ornamentation make it visually striking, while its scientific identification adds to its value and prestige. Fossils of Eubostrychoceras indopacificum are less commonly available than other ammonites, making this specimen particularly special.

For display, its distinctive morphology makes it stand out as a natural work of art, showcasing the evolutionary diversity of ancient marine life. Whether added to a private collection, museum display, or used in educational settings, this ammonite represents a rare opportunity to own a piece of Cretaceous natural history.

Your Guarantee of Authenticity

• 100% genuine Eubostrychoceras indopacificum ammonite fossil from Madagascar
• Geological age: Coniacian stage, Late Cretaceous (approx. 89–86 million years old)
• Supplied with a Certificate of Authenticity
• Exact specimen shown in photographs (no stock images used)
• Scale cube and rule squares = 1 cm (see photos for accurate sizing)

This Eubostrychoceras indopacificum heteromorph ammonite fossil is a rare and scientifically valuable specimen from Madagascar’s world-famous Cretaceous deposits. Its rarity, unusual morphology, and authentic provenance make it a remarkable addition to any serious fossil collection.