Appalachian monkey-face pearly mussel
 The Appalachian monkey-face pearly mussel or Appalachian monkeyface scientific name Quadrula sparsa is a species of freshwater mussel an aquatic bivalve mollusk in the family Unionidae the river mussels. This species is endemic to western Virginia and eastern Tennessee in the Appalachia region in the Southeastern United States. It is critically endangered due to pollution of the rivers in which it lives.