Fossil Ammonite Gagaticeras gagateanum Upper Sinemurian Jurassic Robinhoods Bay UK

Description

Fossil Ammonite – Gagaticeras gagateanum

This listing features a genuine specimen of the ammonite Gagaticeras gagateanum, originating from the world-renowned Robin Hood’s Bay, Yorkshire, United Kingdom. Dating from the Upper Sinemurian stage of the Early Jurassic period (approximately 196–190 million years ago), this fossil captures the extraordinary preservation and diversity of ammonites from this important geological era. The exact specimen photographed is the one you will receive, with a 1 cm scale cube provided for accurate sizing.

Geological Background

The Upper Sinemurian period was a time when much of what is now Yorkshire lay beneath a warm, shallow sea, depositing alternating mudstones and shales that formed the fossiliferous strata of Robin Hood’s Bay. These fine-grained sediments preserved marine fauna in remarkable detail, particularly ammonites, making the site one of Britain’s most significant paleontological localities. Robin Hood’s Bay has long been a focus for fossil collectors and scientists due to its rich sequence of Jurassic rocks, which are crucial for biostratigraphy and global correlation.

Scientific Classification

• Kingdom: Animalia
• Phylum: Mollusca
• Class: Cephalopoda
• Order: Ammonitida
• Superfamily: Eoderoceratoidea
• Family: Oxynoticeratidae
• Genus: Gagaticeras
• Species: Gagaticeras gagateanum

This classification places the specimen within a family of ammonites notable for their elegant shells and diagnostic ribbing patterns.

Morphological Features

Gagaticeras gagateanum is characterised by its slender, moderately involute shell, with fine, regular ribbing running across the flanks. The whorls are compressed and display a smooth yet well-defined profile, giving the fossil a refined and aesthetic form. These features not only make the ammonite taxonomically distinctive but also add to its visual appeal as a display specimen. The ribbing and overall coiling structure provided functional strength to the shell, adapting the organism to its nektonic lifestyle in Jurassic seas.

Paleoenvironment and Significance

Ammonites such as Gagaticeras gagateanum were active, swimming predators inhabiting shallow marine environments rich in life. They likely fed on small crustaceans, molluscs, and plankton, playing an important role in the Early Jurassic food chain. Their rapid evolution and wide geographic distribution make ammonites exceptional index fossils, and Gagaticeras gagateanum is particularly important for refining Upper Sinemurian biozones. Fossils from Robin Hood’s Bay have been central to understanding the stratigraphy and paleoenvironments of the Early Jurassic, contributing to global correlations of Sinemurian sequences.

Provenance and Authenticity

This specimen was collected from the classic fossil-rich deposits of Robin Hood’s Bay, Yorkshire, a location recognised worldwide for the quality and abundance of its ammonites. Each fossil is carefully selected for authenticity, condition, and scientific value. This piece comes with a Certificate of Authenticity, ensuring that it is a genuine ammonite fossil, not a reproduction.

A Unique Collector’s Piece

Owning this Gagaticeras gagateanum ammonite is an opportunity to acquire a rare and scientifically significant fossil from one of the UK’s most famous Jurassic localities. Its elegant ribbed morphology and well-preserved shell structure make it a superb addition to any collection, whether for scientific study, education, or display. This fossil is more than a natural history specimen—it is a tangible connection to the thriving seas of the Early Jurassic, preserved for over 190 million years in the cliffs of Yorkshire.