Crinoid and Blastoid Fossil Plate DX3739

Globoblastus norwoodii and Uperocrinus pyriformis Approx. Dimensions: 3.5 x 3.5 x 2 inches Approx. Weight: 275 grams Mississippian period Burlington formation Marion County, Missouri Acrylic base and mineral putty are not included. From Marion County, Missouri, this is a cool plate with lovely little blastoid and a large crinoid fossil embedded in a matrix with dozens of other small crinoid pieces. This piece lays flat for display, or could be displayed upright with the help of mineral putty (not included). Blastoids (class Blastoidea) are an extinct type of stemmed echinoderm, often referred to as sea buds. They first appear, along with many other echinoderm classes, in the Ordovician period, and reached their greatest diversity in the Mississippian subperiod of the Carboniferous period. However, blastoids may have originated in the Cambrian. Blastoids persisted until their extinction at the end of Permian, about 250 million years ago. Although never as diverse as their contemporar