Early Ordovician extinctions

mass extinction event; occurred approximately 488 million years ago

Choia is a genus of extinct demosponge ranging from the Cambrian until the Lower Ordovician periods. Fossils of Choia have been found in the Burgess Shale in British Columbia; the Maotianshan shales of China; the Wheeler Shale in Utah; the Itajaí Basin in Brazil; and the Lower Ordovician Fezouata formation. It was first described in 1920 by Charles Doolittle Walcott.