Neosilesites ambatolafiensis Ammonite Fossil Rare Iridescent Lower Albian Cretaceous Madagascar

Description

Rare Neosilesites ambatolafiensis Iridescent Ammonite Fossil from Madagascar

Presented here is a highly desirable Neosilesites ambatolafiensis ammonite fossil from the Lower Albian stage of the Early Cretaceous period, dating back approximately 113–107 million years. This exceptional specimen comes from Mitsinjo, Madagascar, a locality world-renowned for producing ammonites with natural aragonite iridescence, giving them a shimmering play of colour under light. The piece photographed is the exact specimen you will receive, with a scale cube of 1 cm shown for accurate size reference. As with all of our fossils, it comes complete with a Certificate of Authenticity, guaranteeing its genuine nature and provenance.

Geological Setting – Lower Albian, Early Cretaceous

The Albian stage forms part of the Early Cretaceous, a period of dynamic geological change and widespread marine environments. The Lower Albian is characterised by global transgressions where warm, shallow epicontinental seas expanded across much of the planet. Madagascar, during this time, was positioned along the western margin of the ancient Gondwana supercontinent, forming part of the tropical margins of the Tethys Ocean.

Sediments deposited in this environment include fine clays, marls, and limestones, providing ideal conditions for the preservation of delicate marine organisms such as ammonites. The fossil record of the Mitsinjo region is especially rich, with ammonites like Neosilesites ambatolafiensis serving as critical biostratigraphic markers for Lower Albian strata.

Scientific Classification

• Fossil Type: Ammonite
• Species: Neosilesites ambatolafiensis
• Age: Lower Albian, Early Cretaceous (c. 113–107 million years ago)
• Locality: Mitsinjo, Madagascar
• Order: Ammonitida
• Superfamily: Desmoceratoidea
• Family: Desmoceratidae

Morphological Features

The genus Neosilesites and particularly the species N. ambatolafiensis are recognised for their distinctive and attractive shell morphology:

• Shell Form: Planispiral, moderately evolute coiling with whorls that are laterally compressed but well defined.
• Ornamentation: Fine ribbing and suture lines, characteristic of the Desmoceratidae family, offering diagnostic features for species identification.
• Surface Preservation: Exceptional preservation of original aragonite layers has produced vivid iridescence, with hues of green, gold, violet, and blue shifting under light.
• Diagnostic Traits: The proportional relationship between whorl height and breadth, combined with rib orientation, makes this species distinguishable within its genus.

This iridescence, combined with strong preservation of shell details, makes the specimen both scientifically valuable and aesthetically striking.

Paleontological Importance

Ammonites such as Neosilesites ambatolafiensis hold special significance for paleontologists due to their role in defining biozones within the Albian stage. Members of the Desmoceratidae family were widespread, evolving rapidly and thus serving as excellent index fossils for global correlation of Lower Cretaceous deposits.

As nektonic predators, ammonites were active swimmers that hunted in the open seas, preying on smaller marine creatures such as crustaceans and mollusks. Their widespread distribution and fast evolutionary turnover make them a cornerstone of stratigraphy, while their striking shells continue to fascinate collectors and researchers alike.

Depositional Environment of Mitsinjo, Madagascar

The Mitsinjo region of Madagascar preserves evidence of tropical shallow marine environments of the Early Cretaceous. These warm, nutrient-rich seas provided an ideal habitat for ammonites, belemnites, fish, and a diverse array of invertebrates. Periods of rapid sedimentation buried ammonites like Neosilesites soon after death, promoting fossilisation and the preservation of delicate shell features.

The unique geochemical conditions of the area allowed for the retention of aragonite layers, responsible for the shimmering iridescent play of colour so highly prized in Madagascan ammonites. This natural beauty, combined with scientific importance, makes these fossils a highlight for any serious collection.

Collector and Display Value

This Neosilesites ambatolafiensis ammonite fossil is not only a scientifically important specimen but also an object of natural beauty. Its natural iridescence makes it a stunning display piece, suitable for private collections, museums, or as an educational tool. Madagascan ammonites are globally sought after due to their unique preservation and striking visual qualities, and this specimen represents an outstanding opportunity to acquire a piece of Early Cretaceous history.

The specimen is supplied with a Certificate of Authenticity, confirming its genuine nature and provenance. The fossil shown in the photographs is the exact piece you will receive, ensuring clarity, transparency, and collector confidence.

Key Details

• Fossil: Neosilesites ambatolafiensis Ammonite
• Age: Lower Albian, Early Cretaceous (c. 113–107 million years old)
• Locality: Mitsinjo, Madagascar
• Classification: Order Ammonitida – Superfamily Desmoceratoidea – Family Desmoceratidae
• Features: Natural iridescence with fine ribbing and preserved suture detail
• Supplied with Certificate of Authenticity
• Exact specimen photographed with 1 cm scale cube

This rare Neosilesites ambatolafiensis ammonite fossil from Madagascar captures both the scientific importance of Albian ammonites and the natural beauty of iridescent preservation, making it an extraordinary acquisition for collectors.