Discinida is an order of brachiopods comprising the extant superfamily Discinoidea, and the extinct superfamilies Botsfordioidea (earlyâÂÂmid-Cambrian) and Acrotheloidea (early CambrianâÂÂEarly Ordovician). It represents a sister taxon to the Lingulids, and is possibly paraphyletic with respect to the Acrotretoids.âÂÂor the acrotretids are paraphyletic with respect to it. The group displays a broad range of shell structures, some of which incorporate substantial organic or silicified components.