Pentagenia robusta
Pentagenia robusta, the robust burrowing mayfly,  is a recently extinct species of mayfly in the family Ephemeridae. It was endemic to the United States, found in the states Indiana, Kentucky, 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. References

Mayflies
Insects described in 1926
Extinct insects since 1500
Extinct animals of the United States
Taxonomy articles created by Polbot