Description: Conulariids have been a subject of speculation for over a century and a half. They ranged from the Middle Ordovician to the Triassic. Exactly what they were is still not settled. Because of their fourfold symmetry, they have often been placed in the Cnidaria. However, their skeleton was very different from anything known in the Cnidaria, and they may represent a separate, extinct phylum The Conulariids had elongated, pyramidal exoskeletons, made up of rows of calcium phosphate rods. Most were square or rectangular in cross section, with prominent grooves at the corners. They lived attached to hard objects by a flexible stalk, and often lived in groups. They are thought to have been filter feeders; how they reproduced is not known.