Brachiopod -

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

They are divided into two main groups: Inarticulates (no hinges, simple muscle systems) and Articulates (hinged with a complex system). brachiopod

They were the most common shelled macroinvertebrates in the Paleozoic era. While decimated by the end-Permian mass extinction, they

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. Unlike bivalves (clams), where shells are mirror images

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

Brachiopods are fascinating marine invertebrates often mistaken for clams, but they are entirely different organisms with a rich, 550-million-year history. Known commonly as "lamp shells," they were dominant in Paleozoic seas but are now relatively rare, often found in deep or cold waters.

They resemble ancient Roman oil lamps, especially the Terebratulida order.