Pentagenia robusta
The robust burrowing mayfly, Pentagenia robusta is a recently extinct species of mayfly in the family Ephemeridae. It was endemic to the United States, found in the states Indiana, Kentucky, Minnesota and Ohio.
It was known only from the Ohio River area and it was not described until 1926. This riverine species was probably sensitive to changes in river flow and water quality, especially increasing sedimentation as are many closely related species.