DetailsPentremites sp. blastoid collected from the Mississippian Indian Springs Shale Formation in Crawford County, Indiana, USA. Pentremites belong to the class Blastoidea and they are a type of echinoderm. They resemble their distant relatives, the crinoids, being attached to the sea floor by a stalk, trapping food with tentacle like appendages. These specimens are of B grade and they measure approximately 1 cm in diameter. Supplied in small plastic bags with an information label.