Definitions

1. noun

an extinct class of echinoderms, the blastoids, that lived during the Paleozoic Era.

“The fossil remains of blastoidea were discovered in the ancient rock formation.”

2. noun

a subclass of the extinct class of echinoderms, the blastoids, characterized by a rounded body and short arms.

“The scientist specialized in studying blastoidea fossils from the Paleozoic Era.”