Arnioceras Multi Block Fossil Ammonites Black Ven Marls Lower Lias Jurassic Coast Black Ven Lyme Regis Dorset UK

Description

Authentic Arnioceras Multi Block Fossil Ammonites from Lyme Regis

This listing is for a genuine Arnioceras multi block fossil ammonite specimen collected from the Black Ven Marls, Lower Lias, at Black Ven, Lyme Regis, Dorset, UK. The block preserves multiple ammonites together within the natural stone matrix, creating a highly attractive and scientifically important display piece. Dating back to the Lower Jurassic, approximately 200 million years ago, this specimen represents a fascinating window into Britain’s ancient seas. The fossil pictured is the exact piece you will receive, with a 1 cm scale cube included for accurate size reference.

The specimen was discovered on 14 September 2025 by our experienced collectors Alister and Alison, and has been carefully cleaned, prepped, and treated by Alison to enhance visibility while maintaining authenticity. It is supplied with a Certificate of Authenticity, confirming it as a 100% genuine fossil with secure provenance.

Geological Context and Age

The Black Ven Marls are among the most famous fossil-bearing deposits in the world, forming part of the Lower Lias succession exposed on the Dorset Jurassic Coast. Recognised as a UNESCO World Heritage Site, this coastline has yielded some of the finest Jurassic fossils known to science.

The Black Ven Marls were deposited in shallow marine environments where fine-grained clays and silts settled on the seabed, entombing marine life. The abundance of ammonites in these layers makes them critical for biostratigraphy, with genera such as Arnioceras serving as key index fossils to precisely date Jurassic strata.

Species Information – Arnioceras

Arnioceras is an extinct genus of ammonites belonging to the order Ammonitida, superfamily Eoderoceratoidea, and family Arietitidae. These ammonites are characterised by their relatively evolute shells, in which the earlier whorls remain visible, and their bold ribbing that often bifurcates as it crosses the shell’s surface. This gives the ammonite a distinctive ornamentation, setting it apart from other Lower Jurassic genera.

Ammonites like Arnioceras were nektonic predators, actively swimming in the shallow seas of the Early Jurassic. Their shells not only provide insight into evolutionary history but also serve as a key marker for correlating rock layers across Europe.

Fossil Features and Preservation

This specimen contains multiple Arnioceras ammonites preserved together in a single block. Their strong ribbing, visible coiling, and characteristic whorl patterns are clearly displayed. The marlstone matrix provides natural context, showing how ammonites were buried and preserved in groups on the seafloor.

The careful preparation has revealed the ammonites without overworking the matrix, maintaining both their visual appeal and their scientific value. The multi block format makes the specimen particularly striking, as it showcases not just one fossil but several individuals preserved in association.

Collector and Scientific Significance

Multi block ammonite specimens such as this are especially valuable for both collectors and scientists. They demonstrate the palaeoecological conditions of deposition, revealing that ammonites often occurred in clusters rather than in isolation. For collectors, this means the specimen is not only scientifically significant but also highly decorative and unique.

With its provenance from Black Ven, this fossil comes from one of the most iconic fossil localities in the world, known since the early days of palaeontology. It is a desirable piece for private collections, museums, and educational displays.

A Rare Multi Block from the Jurassic Coast

This Arnioceras multi block fossil ammonite is a remarkable specimen from the Lower Jurassic of Dorset. With its combination of multiple ammonites, striking preservation, and accompanying Certificate of Authenticity, it is a scientifically valuable and visually appealing fossil from Britain’s Jurassic heritage.

All of our Fossils are 100% Genuine Specimens & come with a Certificate of Authenticity.