Bryozoans, tiny aquatic creatures barely discernible by the naked eye, have fossils that are remarkably common worldwide, particularly in certain North American regions where their calcium carbonate skeletons form entire limestone beds. With nearly 6,000 living species and over 15,000 extinct species dating back at least 480 million years, these species exhibit diverse appearances and behaviors. Bryozoan colonies comprise many semi-autonomous, hermaphroditic clones, known as zooids, that construct coral-like structures to inhabit. This fossil is a branch from one such structure, featuring small pits on its surface, each once housing a single zooid that fed on microscopic organisms. Despite the Permian/Triassic extinction event wiping out 96% of marine life, bryozoans persevered and thrived in the Mesozoic era. Theme Geology Brand Name THE STEMCELL SCIENCE SHOP Manufacturer Stemcell Science Shop Material Type Calcium Carbonate Age Range Description Youth Educational Objective Concept Development Skills, Observation Skills, Patterning