Bifericeras bifer Ammonite Fossil Upper Sinemurian Jurassic Castle Carey Somerset UK

Description

Rare Bifericeras bifer Ammonite Fossil

This listing features a genuine Bifericeras bifer ammonite fossil from the Upper Sinemurian stage of the Early Jurassic, dating to approximately 196–190 million years ago. The specimen was discovered near Castle Carey, Somerset, United Kingdom, a locality known for its rich Jurassic deposits. This carefully chosen fossil is photographed to show the exact piece you will receive, with a 1 cm scale cube for precise sizing. A Certificate of Authenticity is included, ensuring the fossil’s genuineness and provenance.

Geological Setting

The Upper Sinemurian stage is an important interval in the Early Jurassic, notable for its diverse and abundant ammonite fauna. During this time, much of Britain was submerged beneath shallow seas, which provided ideal conditions for marine life to thrive. The Castle Carey area preserves sedimentary rocks that record these ancient environments, capturing ammonites like Bifericeras bifer in fine detail. These ammonites are particularly significant in stratigraphy, as they serve as reliable index fossils for dating and correlating Sinemurian strata across Europe.

Scientific Classification

• Kingdom: Animalia
• Phylum: Mollusca
• Class: Cephalopoda
• Order: Ammonitida
• Superfamily: Eoderoceratoidea
• Family: Eoderoceratidae
• Genus: Bifericeras
• Species: Bifericeras bifer

Morphological Features

Bifericeras bifer is instantly recognisable for its evolute shell form, with all whorls exposed rather than concealed. The whorls are relatively compressed with fine but distinct ribbing, radiating across the flanks and sometimes showing bifurcation as they cross the venter. This ribbing gave the shell both strength and hydrodynamic efficiency. The overall symmetry and rib pattern make this species a striking example of Early Jurassic ammonite morphology, and a sought-after specimen for collectors and paleontologists alike.

Paleoenvironment and Ecology

These ammonites lived in shallow marine settings, where they were nektonic carnivores, preying on smaller invertebrates and planktonic organisms. Their buoyant shells and jet-propelled locomotion would have allowed them to move actively through the water column. The seas around Somerset during the Sinemurian were part of a larger European marine corridor, teeming with ammonites, belemnites, early fish, and marine reptiles. Fossils like Bifericeras bifer provide vital insights into the ecological dynamics of these ancient seas.

Stratigraphic and Scientific Importance

Bifericeras bifer plays an important role in biostratigraphy, particularly in defining the Bifericeras bifer Biozone of the Sinemurian. Its widespread distribution and distinctive morphology make it invaluable for correlating rock layers across different regions. This adds significant scientific value to the fossil beyond its beauty and collectability.

Provenance and Authenticity

This specimen comes directly from Castle Carey, Somerset, a classic locality for British Jurassic ammonites. It has been selected for its preservation quality and clarity of diagnostic features. Every fossil we sell includes a Certificate of Authenticity, guaranteeing its identification and origin.

A Collectible Piece of Jurassic History

This Bifericeras bifer ammonite fossil represents a rare opportunity to acquire an iconic Early Jurassic species from a classic English site. With its fine preservation, historical significance, and secure provenance, it makes an exceptional addition to any collection of ammonites, Jurassic fossils, or natural history specimens.