First appeared in the fossil record roughly 550 million years ago, early in the Cambrian period.
Composed of calcium carbonate (articulates) or calcium phosphate and chitin (inarticulates). brachiopoda
While considered a "minor" phylum today, they were dominant in Paleozoic marine ecosystems and are invaluable as index fossils . First appeared in the fossil record roughly 550
Are you focusing more on their or their use as fossils ? I can expand any of these sections with more specific data. Brachiopods: They're Not Clams held together by muscles.
Severely impacted by the end-Permian extinction (~252 Ma), losing most of their diversity.
Brachiopods represent one of the most persistent and successful lineages in Earth's history.
Lack complex hinges, held together by muscles.