9.4" Fossil Brachiopod (Rafinesquina) and Bryozoan Plate - Indiana

Bryozoans are microscopic aquatic invertebrates that live in colonies, forming skeletal structures similar to corals. Each skeletal structure has a form unique to each particular species. The individual byrozoans forming these colonies are fileter feeders called zooids, straining nutrients from the surrounding water.

Trilobites were a very diverse group of extinct marine arthropods. They first appeared in the fossil record in the Early Cambrian (521 million years ago) and went extinct during the Permian mass extinction (250 million years ago). They were one of the most successful of the early animals on our planet: over 25,000 species have been described, filling nearly every evolutionary niche. Due in large part to their hard exoskeletons (shells), they left an excellent fossil record.