extinct colonial corals tabulatoidea of the carboniferous period (carbon)

ancient animal background bivalve tabulatoidea corals colonial brown cambrian closeup detail epifaunal evolution exoskeleton extinct extinction feeders find formation fossil fossilized fossils geologic geological geology island isolated klint limestone macro marine mollusk natural paleontology period russia saaremaa sea seashell shell silurian specimen spiriferida spiriferidae sprier suspension white