Brachiopods (from Latin brachium, arm + New Latin -poda, foot) are a small phylum of benthic invertebrates. Also known as lamp shells (or lampshells), "brachs" or Brachiopoda, they are sessile, two-valved, marine animals with an external morphology superficially resembling bivalves to which they are not closely related. It is estimated by paleobiologists that 99 percent of all documented brachiopod species are both fossils and extinct. On July 16, 1986, the Kentucky State Legislature designated the brachiopod to be the official Kentucky state fossil.