Rare Large Block Chlamys Aspersa Fossil Bivalves with Echinoid Cambridge Greensand Jurassic Barrington Pit

Description

Rare Chlamys aspersa Fossil Bivalves with Echinoid

This listing offers a rare and impressive fossil specimen: a large block containing multiple Chlamys aspersa fossil bivalves preserved alongside a well-defined regular echinoid. The specimen comes from the famous Cambridge Greensand deposits, specifically Barrington Pit in Cambridgeshire, a location celebrated for its diverse Jurassic fossil assemblages. The fossil block is shown in the photographs with a 1 cm scale cube, ensuring you can clearly see the true size and detail of this unique piece. You will receive the exact specimen pictured, making this a genuine one-of-a-kind addition to any fossil collection.

Geological Setting and Age

The fossil originates from the Cambridge Greensand, a notable unit within the Cretaceous strata that often contains reworked fossils from older Jurassic layers. The Barrington Pit exposures are particularly significant, preserving a mixture of Jurassic fossils redeposited into younger sediments. This block reflects the richness of the deposit, containing beautifully preserved Chlamys aspersa bivalves alongside a regular echinoid. The Greensand environment represents shallow marine depositional conditions, with shifting currents and sedimentary reworking helping to concentrate and preserve these fossils.

Chlamys aspersa – The Fossil Bivalves

Chlamys aspersa is a species of scallop belonging to the family Pectinidae. These bivalves are characterised by their fan-shaped shells, often with radiating ribs and concentric growth lines that create a distinctive ornamented surface. Scallops such as Chlamys aspersa lived freely on the seafloor, capable of limited swimming by rapidly clapping their shells together. Their presence within this fossil block provides valuable insight into Jurassic marine faunas and the adaptive success of pectinid bivalves during this time.

Regular Echinoid Fossil

Alongside the bivalves, this specimen features a regular echinoid. Regular echinoids are members of the Echinoidea, distinguished by their radial symmetry and typically spherical to oval test. They are relatives of modern sea urchins and are characterised by their rigid calcareous shells covered in tubercles where spines were once attached. This echinoid adds significant scientific and aesthetic value to the block, illustrating the diversity of marine life preserved within the Cambridge Greensand deposits.

Depositional Environment

The Cambridge Greensand is well known for its marine origin, laid down under shallow sea conditions. Currents and sedimentary processes led to the mixing of fossils from different horizons, creating fossil-rich concentrations like the one seen here. This environment was home to a variety of invertebrates, including bivalves, echinoids, ammonites, and brachiopods, many of which are preserved in exquisite detail. Fossils from this deposit are historically important, having been studied since the 19th century, and continue to be highly sought after by collectors and researchers alike.

A Carefully Chosen Specimen

This large fossil block was selected for both its scientific value and its display appeal. The association of multiple Chlamys aspersa bivalves with a regular echinoid in a single piece makes it an unusual and desirable specimen, ideal for collectors of rare fossils or as a striking display piece for educational purposes. The preparation of the specimen has ensured that the natural details of the shells and echinoid test are preserved for close study.

Authenticity and Guarantee

All of our fossils are 100% genuine specimens and come with a Certificate of Authenticity. This block has been sourced directly and represents the exact piece shown in the photographs. Unlike casts or replicas, this is a natural fossil formed over millions of years and preserved within its original matrix.

A Unique Collector’s Fossil

This rare combination of Chlamys aspersa fossil bivalves and a regular echinoid from the Cambridge Greensand makes this block a truly exceptional specimen. With its blend of scientific importance, historical context, and natural beauty, it is an outstanding piece for collectors, museums, or anyone with a passion for palaeontology.