The Carolina heelsplitter (Lasmigona decorata) is a species of freshwater mussel, an aquatic bivalve mollusk in the family Uniondae. It is named the "Carolina Heelsplitter" because of its sharp edges protrude and could cut the foot of someone walking on the river or stream bed. This species is endemic to the United States and is found only in the Carolinas. The Carolina heelsplitter was classified as critically endangered by the U.S. Fish and Wildlife Service in 1993.