Cardiaster cordiformis Fossil Echinoid Cretaceous Chalk England Authentic Certified | Rare Sea Urchin from Winchester Quarry

Description

Authentic Cardiaster cordiformis Fossil Echinoid from England

This listing features a fine example of the Cardiaster cordiformis fossil echinoid from the Cretaceous chalk of Smes Loo Quarry, W. Tisted, near Winchester, England. Cardiaster is a distinctive genus of fossil heart urchins, well known for its elegant heart-shaped form and its role as an important marker fossil within the chalk formations of southern England. The specimen offered here is the actual fossil shown in the photographs, with a 1 cm scale cube included for accurate sizing.

All of our fossils are 100% genuine specimens, and each purchase is supplied with a Certificate of Authenticity, making this a valuable addition for collectors, educators, and those fascinated by the natural history of Britain’s prehistoric seas.

Geological Age and Formation

This specimen comes from the Cretaceous Period (145–66 million years ago), specifically from chalk deposits that formed in warm shallow seas covering much of southern England. The chalk of Smes Loo Quarry is part of a sequence of fine-grained limestones deposited during the Late Cretaceous, composed mainly of coccolithophores (microscopic plankton). These sediments provided ideal conditions for the preservation of echinoids like Cardiaster cordiformis.

The Winchester region is famous for its rich chalk exposures and has yielded numerous well-preserved fossil echinoids, making it a classic British fossil locality.

Fossil Type and Classification

• Species: Cardiaster cordiformis
• Genus: Cardiaster
• Order: Spatangoida
• Superfamily: Cardiasteridea
• Family: Cardiasteridae

This genus is one of the most recognisable fossil echinoids from the chalk seas of Europe. Cardiaster cordiformis is especially notable for its elegant, cordate (heart-shaped) test and has long been prized both scientifically and aesthetically.

Morphological Features

The morphology of Cardiaster cordiformis is striking and diagnostic, displaying:

• A distinct heart-shaped outline, wider at the anterior and tapering towards the posterior.
• A deep frontal groove (sulcus) running from the apical system towards the anterior, reflecting adaptations for sediment feeding and burrowing.
• Petaloid ambulacra arranged in a symmetrical star-like pattern across the dorsal surface.
• A flattened ventral surface with a centrally positioned peristome (mouth) and posteriorly located periproct (anal opening).

These adaptations allowed Cardiaster cordiformis to live as an infaunal deposit feeder, burrowing within soft chalk sediments and feeding on organic matter.

Scientific and Collector Value

Cardiaster cordiformis is an important biozonal index fossil, used in stratigraphic studies of the Late Cretaceous chalk. Its evolutionary significance lies in its specialised adaptations to soft-sediment life, making it a valuable study subject for palaeontologists.

For collectors, this specimen is an excellent representation of a classic English chalk echinoid, appreciated for both its scientific significance and natural beauty. Its elegant heart shape makes it a visually striking fossil, perfect for display in a fossil cabinet, educational context, or private collection.

Depositional Environment

The chalk seas of southern England during the Cretaceous were shallow, warm, and nutrient-rich, teeming with microscopic life. These conditions supported abundant marine organisms, including echinoids, ammonites, and fish. The fine-grained chalk provided excellent preservation potential, capturing the delicate forms of echinoids like Cardiaster cordiformis in remarkable detail.

Guarantee of Authenticity

Every specimen we offer is 100% genuine, carefully selected for its preservation and scientific interest. A Certificate of Authenticity is provided with each fossil, ensuring its provenance. The specimen in the photographs is the exact fossil you will receive, with full sizing shown against a scale cube.

This Cardiaster cordiformis fossil echinoid from the chalk of Winchester, England offers a rare chance to own a beautifully preserved piece of Britain’s Cretaceous past – a fossil that combines scientific importance with timeless natural beauty.