Brachiopod -

Here is a review of their significance, biology, and fossil record. 🌟 Key Takeaways

While decimated by the end-Permian mass extinction, they are not extinct, with ~400+ extant species. 🔬 Biology and Lifestyle

They are benthic (sea-floor dwellers) and sessile (permanently attached to the seafloor), generally filter-feeding.

Unlike bivalves (clams), where shells are mirror images of each other, brachiopod shells are top/bottom oriented and distinct, but each individual valve is symmetrical down the middle.