Rare Dufrenoyia dufrenoyi Ammonite Fossil from Lower Aptian Cretaceous Tulear Madagascar Authentic Specimen

Description

Geological Context and Provenance

This rare specimen is a genuine Dufrenoyia dufrenoyi fossil ammonite from the Lower Aptian Stage of the Early Cretaceous Period, dating to approximately 125 – 113 million years ago. It was discovered in the Tulear region of Madagascar, an area internationally renowned for its rich deposits of well-preserved Cretaceous ammonites. Madagascar’s fossil sites have long been prized for the quality and variety of ammonite faunas, offering both scientific insight and collector appeal.

During the Aptian, Madagascar was located within the southern reaches of the ancient Tethys Ocean. The warm, shallow seas and fine-grained sediments of the region provided excellent conditions for the preservation of ammonite shells. Fossils from Tulear are often found with remarkable clarity in ribbing and whorl structure, making them highly desirable specimens for collectors and researchers alike.

Fossil Type and Species Information

Dufrenoyia dufrenoyi belongs to the Order Ammonitida, Superfamily Desmoceratoidea, and Family Parahoplitidae. The genus Dufrenoyia is a significant component of Lower Aptian ammonite faunas and is widely used as an index fossil, helping geologists establish and refine the stratigraphy of the Aptian Stage.

The species dufrenoyi is characterised by its distinctively ribbed and ornamented shell, with features that make it a standout among Aptian ammonites. Its wide distribution and clearly defined morphological traits make it especially valuable for both scientific classification and private collections.

Morphological Features and Identification

This specimen displays the diagnostic features of Dufrenoyia dufrenoyi, including strong, bold ribbing that extends across the flanks and onto the venter. The ribs may bifurcate or branch, adding a sculptural quality to the fossil. The whorls are moderately involute, forming a compact and well-proportioned shell.

The ribbing served multiple purposes, reinforcing the shell against water pressure and predation, while also improving hydrodynamic efficiency as the animal swam in open water. As with other ammonites, the chambered interior of the shell allowed the creature to regulate buoyancy, enabling it to live as an active nektonic predator.

Depositional Environment

The Tulear deposits formed in shallow marine environments associated with the southern Tethys Ocean. Fine limestones and marls accumulated over millions of years, encapsulating ammonite shells in layers that preserved their detail. These seas were rich ecosystems teeming with life, from ammonites and belemnites to bivalves, gastropods, echinoids, and larger marine reptiles.

Dufrenoyia dufrenoyi played a key role in this ecosystem, preying on smaller invertebrates and planktonic organisms while serving as food for apex predators such as ichthyosaurs and pliosaurs. Its abundance and broad distribution make it an important fossil for understanding Aptian marine biodiversity.

Collector Appeal and Authenticity

This Dufrenoyia dufrenoyi ammonite fossil is a scientifically valuable and visually impressive specimen. Its strong ribbing, elegant shell form, and provenance from Tulear, Madagascar, make it highly desirable for collectors, educators, and natural history enthusiasts.

• 100% Genuine Specimen – Every fossil we supply is authentic and provided with a Certificate of Authenticity.
• Exact Fossil Shown – The photographs depict the actual specimen you will receive.
• Scale Reference – Scale rule squares / cube = 1 cm. Please refer to images for precise sizing.

This carefully selected Dufrenoyia dufrenoyi ammonite fossil offers a unique opportunity to own a rare piece of Early Cretaceous history. With its combination of rarity, scientific importance, and aesthetic appeal, it is an exceptional addition to any fossil collection or natural history display.