Pleurobema curtum

This species is endemic to the United States, and historically occurred in the Tombigbee River in Alabama and Mississippi.

At the time of its endangered listing in 1987, only two live individuals were known to have been ever collected, and populations were limited to the East Fork.

[3] The species was likely adversely affected by impoundments on the Tombigbee River and construction of the Tennessee-Tombigbee Waterway in 1985, which altered water flow, increased siltation, and disturbed habitat by dredging.

Fresh dead shells were found in 1997 on a single shoal in the East Fork Tombigbee River in Itawamba County, Mississippi, and further surveys have been unsuccessful.

As of the latest 5-year review by US Fish and Wildlife Service in 2021, no recent searches had been made, and it is possible the species still persists.