Ataxioceras hypselocyclum Ammonite Fossil Dorset Jurassic with COA

Description

Genuine Ataxioceras Ammonite Fossil

This genuine ammonite fossil is identified as Ataxioceras hypselocyclum and comes from Dorset in the United Kingdom. It is from the Kimmeridge Clay Formation and dates to the Lower Kimmeridgian Stage of the Upper Jurassic. The specimen is a carefully selected British fossil with valuable species, formation, age, and locality information. The photographs show the actual fossil offered for sale, so the ammonite pictured is the exact specimen you will receive.

Ataxioceras was an extinct marine cephalopod with a coiled, chambered shell. During growth, the animal added progressively larger chambers around the outer whorl. The living ammonite occupied the final body chamber, while older sealed chambers contributed to buoyancy control. Ammonites were relatives of living squid, cuttlefish, and nautiluses, but belonged to their own extinct and highly diverse group.

Lower Kimmeridgian Geological Age

The Kimmeridgian is a stage within the Late Jurassic Period, approximately 157 to 152 million years ago. During its earlier part, warm marine environments covered extensive areas of Europe and supported diverse ammonites, bivalves, marine reptiles, fish, and other sea life. After death, an ammonite shell could settle onto the sea floor and become buried within fine sediment. Compaction, mineralisation, and geological change then preserved parts of the shell as a fossil.

Ammonites evolved rapidly and were widely distributed through Jurassic seas. Their changing shell forms make them valuable index fossils, helping geologists compare rock layers and establish relative ages. The documented Lower Kimmeridgian age gives this specimen a clear position within the Upper Jurassic succession.

Kimmeridge Clay Formation

The Kimmeridge Clay Formation is one of Britain’s best-known Upper Jurassic geological units. It consists largely of marine mudstones and shales deposited in an ancient sea. Organic-rich intervals and fine sediments preserve a remarkable record of marine ecosystems. Fossils from the formation may retain a combination of shell material, mineral replacement, and surrounding clay-rich matrix.

Dorset has internationally important Jurassic exposures along its coast and inland areas. A specimen with documented Dorset and formation provenance carries more context than an entirely unlocalised fossil. It can complement a collection arranged by British county, geological formation, Jurassic stage, ammonite genus, or ancient marine environment.

Shell Form and Collectable Detail

Ataxioceras ammonites are recognised for their ribbed, evolute coiled shells. Examine the photographs for visible whorls, rib pattern, shell outline, umbilical region, matrix, and preserved surface details on this individual example. Rib strength, branching pattern, whorl proportions, and changes in ornament around the shell are features used when comparing ammonites and interpreting their growth.

Natural colour, mineral texture, small breaks, areas of wear, and variations in preservation reflect the fossil’s long geological history. Every specimen preserves a different balance of original shell, mineral replacement, and surrounding rock. The multiple photographs show this exact piece from useful angles and present its condition, proportions, texture, and natural display character more accurately than a generic image could.

Exact Specimen and Full Sizing

Full sizing is shown in the photographs, which provide the best scale information for this individual fossil. The images are not stock photographs and do not represent a similar piece. They show the exact Ataxioceras hypselocyclum ammonite fossil that will be supplied.

Authenticity and Presentation

This is a genuine fossil specimen and includes a generic Certificate of Authenticity card with a lifetime guarantee. It has been carefully chosen for its identifiable ribbed shell, Kimmeridge Clay Formation context, Lower Kimmeridgian age, Dorset provenance, and natural geological character. It makes a distinctive addition to a cabinet collection, educational display, office, study, or gift for anyone interested in authentic Upper Jurassic fossils, British palaeontology, or ammonite evolution.