Rare Deshayesites forbesi Ammonite Fossil from Aptian Cretaceous Atherfield Isle of Wight United Kingdom Authentic Specimen

Description

Geological Context and Provenance

This rare specimen is a genuine Deshayesites forbesi fossil ammonite from the Aptian Stage of the Early Cretaceous Period, dating to approximately 125 – 113 million years ago. It was discovered at Atherfield, Isle of Wight, United Kingdom, one of the most famous fossil localities in Britain. The Atherfield section exposes marine deposits from the Lower Greensand Formation, which is globally significant for its abundance of Aptian ammonites and other marine fossils.

The Isle of Wight has long been a key site for palaeontological research, providing a wealth of Early Cretaceous fossils. The Aptian seas that once covered this region were part of the vast Tethyan marine system, where ammonites thrived in great diversity. Fossils from Atherfield remain highly sought after, both for their scientific importance and for their rarity in private collections.

Fossil Type and Species Information

Deshayesites forbesi belongs to the Order Ammonitida, Superfamily Deshayesitoidea, and Family Deshayesitidae. The genus Deshayesites is one of the most important ammonite groups of the Aptian Stage and is widely used as an index fossil for defining biozones.

The species forbesi is notable for its distinctive ribbing and whorl morphology, making it easily recognisable to specialists. Its stratigraphic range within the Aptian is well documented, and its distribution across Europe, including classic British localities such as Atherfield, adds further significance to its role in stratigraphy and palaeobiogeography.

Morphological Features and Identification

This specimen of Deshayesites forbesi shows the classic features of the species, including strong, straight to slightly curved ribs that cross the shell flanks and extend over the venter. The whorls are moderately involute, producing a tightly coiled and elegant shell form. The ribbing may occasionally bifurcate, enhancing the ornamental quality of the shell.

These features were functional as well as diagnostic. The ribbing provided structural reinforcement against the pressures of open marine life, while the chambered shell interior allowed buoyancy control. Like all ammonites, Deshayesites was a nektonic predator, pursuing smaller invertebrates in the marine water column.

Depositional Environment

During the Aptian Stage, the Isle of Wight lay beneath shallow seas that formed part of the northern margin of the Tethys Ocean. The Lower Greensand Formation at Atherfield represents a shallow marine depositional setting, where sands, silts, and clays accumulated in conditions that supported diverse marine ecosystems.

The environment hosted abundant ammonites, belemnites, bivalves, gastropods, and marine reptiles. Ammonites like Deshayesites forbesi played a vital ecological role, linking lower trophic levels of plankton and small invertebrates to apex predators such as marine reptiles. Their abundance, diversity, and well-preserved fossils make the Atherfield deposits a reference site for Aptian palaeontology.

Collector Appeal and Authenticity

This Deshayesites forbesi ammonite is a rare and scientifically important fossil from one of Britain’s most iconic fossil localities. Its striking ribbing, excellent preservation, and provenance from Atherfield make it a highly desirable specimen for collectors and researchers alike.

• 100% Genuine Specimen – Every fossil we supply is authentic and accompanied by 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 check the photos for accurate measurements.

This carefully selected Deshayesites forbesi ammonite fossil represents a direct link to the Aptian seas of Early Cretaceous Britain. Combining scientific importance with natural beauty, it makes an exceptional addition to any fossil collection or natural history display.