Pseudocidaris mammosa Echinoid Fossil – Jurassic Kimmeridgian France, Rare Sea Urchin with Spines

Description

An incredibly rare and well-preserved Pseudocidaris mammosa fossil echinoid from the Kimmeridgian Stage of the Late Jurassic, approximately 155–150 million years ago. This spectacular specimen was discovered in the marine limestones of Saint-Clément, Île de Ré, Charente-Maritime, France — a notable fossil locality for Jurassic echinoderms.

This particular specimen includes the central test (body) of the echinoid accompanied by four separated, bulbous club-like spines, characteristic of the Pseudocidaris genus. These spines are rarely found detached and preserved with the test, making this a scientifically and visually exceptional piece.

Fossil Type: Echinoid (Sea Urchin)

Species: Pseudocidaris mammosa

Geological Age: Upper Jurassic – Kimmeridgian Stage

Formation: Kimmeridgian marine limestone beds, likely part of the Falaises de l’Île de Ré sequence

Depositional Environment: These echinoids lived in warm, shallow marine shelf environments with carbonate sedimentation. Their remains were rapidly buried in calcareous muds, contributing to the preservation of both the test and robust spines in fine detail.

Morphological Features:

• Rounded echinoid test with visible tubercles (spine attachment points)
• Four robust, bulbous, club-shaped spines detached but preserved
• Radial symmetry typical of echinoids

Notable:

• Rare occurrence of both test and multiple original spines
• Collected from a premium Upper Jurassic fossil site in France
• Highly desirable for collectors, museums, and academic reference
• The item shown is the exact specimen you will receive

Authenticity: All of our fossils are 100% genuine natural specimens and are supplied with a Certificate of Authenticity. For sizing, each square or cube in the scale equals 1cm – please refer to the included image.

This Pseudocidaris mammosa echinoid fossil is a museum-quality piece from the Jurassic seas of France, offering exquisite preservation and rare associated spines. A true collector’s treasure and scientifically significant specimen.