Formation: St. Louis Formation
Location: St. Louis, Missouri
Size: Plate is 4.35 inches across
This is a very rare and important find. It is a plate of two excellent 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 urchins were found YEARS ago, stored in a box, and just now opened and prepared - when they're all gone, they're GONE! These spiny urchins are larger than the Lepidocidaris found in the Mississippian Warsaw Formation, and are OLDER than the Pennsylvanian Archaeocidaris from Texas. These urchins are complete with MANY barbed spines still intact. Most of the types of urchins from this site have smooth spines (there are three species!), and ones with the barbed spines are rarer. The echinoids display well on the large, natural plate of matrix that also has urchin remnants on the back side. This is a rare double example of Mississippian echinoids from the St. Louis Formation, offered exclusively through EXTINCTIONS.
This fossil was collected and obtained legally, and is also being sold legally.
A Certificate of Authenticity from EXTINCTIONS is included with this specimen.