Archaeocidaris wortheni, Archaeocidaris illinoisensis
Formation: St. Louis Formation
Location: St. Louis, Missouri
Size: Plate is 9.6 inches across!
This is simply an incredible find. It is a HUGE Archaeocidaris wortheni and at least SIX Archaeocidaris illinoisensis 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 spiny urchins are larger than the Lepidocidaris found in the Mississippian Warsaw Formation, and are OLDER than the Pennsylvanian Archaeocidaris from Texas. This large, extremely rare Archaeocidaris wortheni urchin is complete with MANY long spines still intact. The huge echinoid displays well on the large, rectangular plate of limestone that also has SIX fabulous examples of the smaller Archaeocidaris illinoisensis. This is a special fossil, a unique example of two ultra-rare species of Archaeocidaris from the St. Louis Formation.
This fossil was collected and obtained legally, and is also being sold legally.
A Certificate of Authenticity from EXTINCTIONS is included with this specimen.