Order of Brachiopoda, with valves usually of calcium phosphate with some layers of organic material. The valves may be finely punctate or impunctate. The pedicle emerges between the valves posteriorly. Lingulida are usually marine, but some are tolerant of reduced salinity. They appeared first in the Lower Cambrian. There are two superfamilies: the Lingulaceae (which includes Lingulella and the extant Lingula); and the Trimerellaceae, ranging from the Ordovician to the Silurian, with a biconvex, probably aragonitic shell, with internal muscle platforms (e.g. Trimerella, Dinobolus).