Cidarid Echinoid Fossil Jurassic Sea Urchin Burton Bradstock Dorset UK Bridport Sand Formation Lower Jurassic Toarcian

Description

Genuine Cidarid Echinoid Fossil from the Jurassic Coast

This genuine fossil Cidarid echinoid, an ancient sea urchin, originates from the Bridport Sand Formation at Burton Bradstock, Dorset, United Kingdom. Preserved in Lower Jurassic marine sediments dating to the Toarcian stage, approximately 182–174 million years ago, this specimen represents a classic example of an echinoderm that once lived on the seabed of the Jurassic ocean.

The fossil has been carefully selected as an attractive and well-preserved specimen. The photographs show the exact fossil you will receive, allowing collectors to clearly see the preservation and natural features of the echinoid test. Please refer to the photos for the full sizing and proportions of the specimen. This fossil includes a Certificate of Authenticity lifetime guarantee generic card confirming that the specimen is a genuine fossil.

About Cidarid Echinoids – Ancient Sea Urchins of the Jurassic Seas

Cidarid echinoids belong to the order Cidaroida, a group of sea urchins that first appeared during the Paleozoic Era and continue to exist today in modern oceans. These echinoderms are characterised by their rigid skeletal shell known as a test, composed of interlocking calcite plates arranged in symmetrical patterns.

Members of the family Cidaridae are often referred to as pencil urchins due to their thick, robust spines. In life, these spines were attached to large tubercles on the surface of the test and served multiple functions including locomotion, protection from predators, and interaction with the surrounding environment.

The test itself is typically spherical to slightly flattened and displays rows of plates arranged in radial symmetry. Each plate includes attachment points for spines and small openings through which tube feet extended, allowing the animal to move slowly across the seabed.

Morphology and Skeletal Structure

The fossil test of a cidarid echinoid is made up of numerous calcitic plates forming a rigid shell that protected the internal organs of the animal. Prominent tubercles on the plates supported large primary spines that could be several times longer than the body.

Between these larger tubercles were smaller granules and plate structures that supported secondary spines and tube feet. These tube feet functioned as part of the echinoid’s water vascular system, enabling movement, feeding, and interaction with the substrate.

Although the spines are often lost during fossilisation, the preserved test retains the distinctive pattern of plate arrangement and spine attachment points that allow identification of cidarid echinoids.

Geological Setting – Bridport Sand Formation

The Bridport Sand Formation is an important Lower Jurassic geological unit exposed along the Dorset coast, particularly around Burton Bradstock and nearby sections of the Jurassic Coast. This formation consists primarily of fine sandstones and sandy mudstones deposited in a shallow marine environment during the Toarcian stage.

During this time, much of southern Britain was submerged beneath a warm epicontinental sea connected to the broader Tethyan Ocean system. Sediments accumulated on the seabed as sand and fine sediment settled out of the water column.

The Bridport Sand Formation is well known for preserving a diverse range of marine fossils including ammonites, bivalves, brachiopods, and echinoderms such as sea urchins. These fossils provide valuable information about the biodiversity and environmental conditions of the Early Jurassic seas.

Jurassic Marine Environment of Dorset

During the Toarcian stage of the Early Jurassic, the Dorset region supported a thriving marine ecosystem. The shallow seabed environments provided ideal conditions for echinoderms like cidarid sea urchins, which lived among sandy and muddy substrates.

These echinoids likely fed on organic particles, algae, and small organisms found on or within the sediment. Their spines helped them move across the seabed and provided protection against predators such as fish and marine reptiles.

The Jurassic Coast is internationally renowned for its exceptional fossil record, and discoveries from Burton Bradstock contribute significantly to our understanding of Early Jurassic marine life.

Authenticity and Collectability

• Genuine Cidarid echinoid fossil (sea urchin)

• Bridport Sand Formation, Lower Jurassic

• Toarcian stage, approximately 182–174 million years old

• Collected from Burton Bradstock, Dorset, United Kingdom

• The fossil shown in the photographs is the exact specimen you will receive

• Includes a Certificate of Authenticity lifetime guarantee generic card

Fossil echinoids from the Jurassic Coast are highly desirable among collectors due to their distinctive morphology and connection to one of the world’s most famous fossil regions. This Cidarid echinoid from the Bridport Sand Formation represents a fascinating piece of Jurassic marine history and makes an excellent addition to any fossil collection, natural history display, or geological study.