VERY RARE Fossil Ammonite Coroniceras valdanifractum Lower Sinemurian Jurassic Redcar UK

Description

Fossil Ammonite – Coroniceras valdanifractum

This listing presents an exceptional and very rare specimen of Coroniceras valdanifractum, a large and iconic ammonite from the Lower Sinemurian stage of the Early Jurassic (approximately 196–190 million years ago). Sourced from the historically important fossil beds of Redcar, Yorkshire, United Kingdom, this ammonite is a striking collector’s piece. The specimen shown in the photographs is the exact one you will receive, with a 1 cm scale cube provided for accurate measurement.

Geological Context

During the Early Jurassic, much of what is now Yorkshire was covered by shallow seas, part of the extensive European epicontinental shelf. These marine environments were highly productive, supporting diverse communities of invertebrates and marine reptiles. The Lower Lias Group, from which this fossil originates, is world-renowned for its ammonite faunas. Within the Lower Sinemurian, Coroniceras valdanifractum is a significant species, commonly used as an index fossil to refine stratigraphic divisions and date specific horizons.

Scientific Classification

• Kingdom: Animalia
• Phylum: Mollusca
• Class: Cephalopoda
• Order: Ammonitida
• Superfamily: Psiloceratoidea
• Family: Arietitidae
• Genus: Coroniceras
• Species: Coroniceras valdanifractum

This ammonite is part of the Arietitidae family, characterised by robust, heavily ribbed shells often preserved in beautiful detail in Lower Lias sediments.

Morphological Features

Coroniceras valdanifractum is renowned for its massive, thick-shelled, evolute coiling with a wide umbilicus. The ribs are coarse, strong, and widely spaced, extending across the flanks and often bifurcating toward the outer whorl. This distinctive ornamentation gives the ammonite its unmistakable appearance and makes it one of the most sought-after Lower Jurassic ammonite fossils. The strength and thickness of the shell suggest adaptations to an active, nektonic lifestyle, capable of withstanding varying marine conditions.

Paleoenvironment and Importance

Ammonites like Coroniceras valdanifractum inhabited warm, shallow seas, preying on small crustaceans, molluscs, and planktonic organisms. Their rapid evolution and widespread distribution across Jurassic seas made them ideal for biostratigraphy. This species is particularly important within the Sinemurian Valdanifractum Subzone, which bears its name. Specimens from the Yorkshire coast, especially around Redcar and Whitby, have been studied for over two centuries, contributing significantly to the understanding of Jurassic geology and paleontology.

Provenance and Authenticity

Collected from the classic Lower Lias deposits of Redcar, this specimen represents a fine example of a rare ammonite species. Fossils from this region have long been prized by collectors and institutions alike, with many historical specimens preserved in the collections of the Natural History Museum in London and other major institutions. This piece comes with a Certificate of Authenticity, guaranteeing that it is a genuine fossil, not a cast or reproduction.

A Rare Collector’s Piece

This Coroniceras valdanifractum ammonite is more than just a fossil—it is a unique piece of natural history from the Early Jurassic seas of Britain. Its rarity, robust preservation, and scientific importance make it a highly desirable specimen for serious collectors, educators, or as a striking display piece. Few fossils combine such historical significance with visual appeal, making this ammonite a true treasure of paleontology.