Macrophthalmus Fossil Crab Madagascar Pliocene Majunga Province Genuine Specimen COA

Description

Macrophthalmus Fossil Crab – Pliocene, Majunga Province, Madagascar

This rare and beautifully preserved Macrophthalmus fossil crab comes from the Pliocene deposits of Majunga Province in northwestern Madagascar, a region well known for its richly fossiliferous coastal sediments. This specimen represents a fascinating snapshot of marine life from approximately 5.3 to 2.6 million years ago, during a time when Madagascar’s coastlines supported thriving populations of crustaceans, molluscs, corals, and a wide range of marine vertebrates. The fossil shown in the photographs is the exact specimen you will receive, carefully selected for its strong detail, natural character, and excellent preservation. As with all our fossils, it is a 100% genuine specimen and includes a Certificate of Authenticity.

Geological Background – Pliocene Coastal Environments of Madagascar

During the Pliocene epoch, much of Madagascar’s western coastline consisted of warm, shallow marine and estuarine environments. These settings formed as sea levels fluctuated, depositing layers of fine sands, silts, and carbonates rich in marine life. The Majunga Province, in particular, is known for its fossil-bearing sedimentary sequences that accumulated in tidal flats, mangrove-associated environments, and lagoonal systems.

These depositional settings are ideal for preserving crustaceans such as Macrophthalmus, a genus commonly associated with intertidal zones and soft substrates. The gentle burial conditions and steady sedimentation of the Pliocene coastal plains allowed carapaces and claws to be fossilised in situ, often retaining much of their external morphology. The result is a fossil record that offers remarkable insight into the behaviour and ecological roles of ancient crabs.

Scientific Notes on Macrophthalmus

Macrophthalmus belongs to the family Macrophthalmidae, within the superfamily Ocypodoidea and order Decapoda. Members of this genus—often called “stalk-eyed crabs”—are recognised for their elongated eyestalks, flattened bodies, and adaptations suited to life in muddy coastal habitats. Their wide carapace and strong, sharply defined claws reflect their ecological role as both scavengers and detritivores.

This fossilised example preserves many of the characteristic features of the genus, including the broad, sculpted carapace; the symmetry of the orbital regions; and the robust chelae typical of Macrophthalmus species. Specimens from Madagascar often preserve fine surface details, giving collectors a clear window into the anatomy and lifestyle of these ancient crabs.

Palaeoenvironment and Fossil Formation

The Majunga region’s Pliocene sediments were shaped by warm climates, seasonal monsoon patterns, and shifting coastal boundaries. These environmental factors fostered highly productive mangrove and tidal ecosystems where crustaceans played an essential role. When these crabs died, their remains were quickly buried by fine sediments carried by tidal movements or storm surges, minimising decay and scavenging.

Over millions of years, mineral-rich groundwater permeated these layers, gradually replacing organic material with durable minerals while retaining the crab’s three-dimensional shape. This natural fossilisation process results in specimens with strong relief, excellent anatomical definition, and a pleasing visual texture.

A Unique and Highly Collectable Fossil Crab

Macrophthalmus fossil crabs are uncommon, making this specimen an appealing choice for collectors of marine fossils, crustacean specialists, natural history enthusiasts, or those seeking a distinctive display piece with scientific interest. Its geological origin, attractive preservation, and natural aesthetic make it suitable for educational settings, home décor, or museum-style displays.

Please see the listing photographs for full sizing information. The fossil pictured is the exact one you will receive, selected carefully for quality and character. Every fossil we supply is a 100% genuine specimen and comes with a Certificate of Authenticity, ensuring complete confidence in authenticity and provenance.