Sculpted Stone

This is an amazing echinoderm fossil. It is a HUGE Archaeocidaris wortheni echinoid from the Mississippian of St. Louis. Fossil echinoids from the St. Louis area are famous around the world and have been extremely sought-after by collectors for decades. These rare urchins are LARGER than the Lepidocidaris found in the Mississippian Warsaw Formation, and are OLDER than the Pennsylvanian Archaeocidaris from Texas. This gigantic Archaeocidaris wortheni urchin is complete with many, MANY of its long spines still intact. The individual plates and spine attachment nodes are easily seen. The extremely detailed echinoid displays beautifully on the large, rectangular plate of shale. This is a very impressive and extremely collectible fossil Archaeocidaris echinoid from the St. Louis Formation.

A Certificate of Authenticity from EXTINCTIONS is included with this specimen.