https://www.selleckchem.com/pr....oducts/cm272-cm-272.
Most sponges produce skeletons formed by spicules, structural elements that develop in a wide variety of sizes and tridimensional shapes. The morphologies of spicules are often unique to clade- or even species-level taxa which makes them particularly useful in taxonomic assignments. When dead sponge bodies disintegrate, spicules become incorporated into sediments and sometimes accumulate into enormous agglomerations called spicule mats or beds, or fossilize to form special type of rocks called the spiculites. The record of fossil a