Micraster Echinoid Fossil Polished Cretaceous Spain Genuine with Certificate

Overview & Authenticity

This listing features a genuine Micraster echinoid fossil, professionally polished to enhance its natural structure and detail, originating from the Cretaceous deposits of Spain. This specimen has been carefully selected for its preservation quality, pleasing shape, and strong display appeal. The photographs show the actual fossil you will receive, ensuring complete transparency and confidence when purchasing.
Every fossil is supplied with a Certificate of Authenticity, including a lifetime guarantee of genuineness, provided on a generic authenticity card. This ensures that the specimen is a true natural fossil and a secure addition to any collection.

Geological Age & Cretaceous Setting

Micraster fossils date to the Late Cretaceous Period, approximately 100–66 million years ago, a time when much of Europe, including Spain, was covered by warm, shallow epicontinental seas. These marine environments were rich in carbonate sediment and supported abundant invertebrate life, including echinoids, molluscs, and ammonites.
The chalky limestones and marine sediments of Cretaceous Spain provided ideal conditions for fossil preservation, allowing echinoids such as Micraster to be buried rapidly and fossilised in excellent three-dimensional form.

Fossil Type & Scientific Classification

Micraster is an extinct genus of irregular echinoid (heart urchin), belonging to the class Echinoidea. Unlike modern spiny sea urchins, Micraster was adapted for life partially buried in sediment, moving through soft seabeds in search of organic material.

• Phylum: Echinodermata

• Class: Echinoidea

• Order: Spatangoida

• Genus: Micraster

Micraster is one of the most iconic and widely collected Cretaceous echinoids, valued for both its distinctive heart-shaped form and its importance in stratigraphy.

Morphology & Notable Features

This specimen displays the characteristic heart-shaped outline of Micraster, with clearly defined symmetry and surface details. Features often visible include the petaloid ambulacra (the flower-like pattern on the upper surface), subtle growth ridges, and the distinctive profile of an irregular echinoid adapted for burrowing.
The polishing process enhances contrast and reveals internal texture and surface structure while preserving the fossil’s natural form. Polished Micraster fossils are especially popular because they highlight anatomical details that may be harder to see on unprepared specimens.

Depositional Environment & Fossilisation

During the Late Cretaceous, Micraster lived on shallow marine seabeds composed of soft carbonate mud. These echinoids burrowed just beneath the sediment surface, feeding on detritus and organic particles. After death, the tests were buried by continued sedimentation, protecting them from breakage and scavenging.
Over millions of years, mineral replacement and lithification transformed the original calcitic shell into stone, preserving the fossil in remarkable detail.

Collecting & Display Appeal

Polished Micraster fossils from Spain are highly sought after due to their elegant natural form, scientific significance, and refined presentation. This specimen is ideal for fossil collectors, educational collections, interior display, or as a unique prehistoric gift.
Full sizing details are provided in the photographs. As a carefully chosen, genuine Cretaceous echinoid fossil supplied with a Certificate of Authenticity and lifetime guarantee, this Micraster represents a tangible connection to ancient seas and is a striking addition to any fossil collection.