Blastoid
Blastoids are an extinct group of marine animals belonging to the phylum Echinodermata, making them distant relatives of crinoids, sea stars, and sea urchins. Commonly referred to as “sea buds” due to their distinctive, bud-like shape, blastoids were sessile filter feeders that lived attached to the seafloor by a stalk during the Paleozoic Era, particularly thriving in the Mississippian period (roughly 359-323 million years ago).
Fossils like Pentremites are among the most well-known blastoids found in regions like Northwest Pennsylvania and Northeast Ohio, where ancient shallow seas once teemed with marine life. The main body of a blastoid, called the theca, is typically preserved with remarkable detail. Its rigid, patterned plates and star-shaped food grooves (ambulacra) offer a fascinating look at how these ancient creatures captured nutrients from the water.
Although long extinct, blastoids are prized by fossil hunters for their unique structure and evolutionary significance. Their remains are a testament to the rich and diverse life that once flourished in prehistoric seas of the Ohio Valley region.
Found on these trips:
Found in these locations:
Photos of Blastoid
From trip: Lake Erie in August
