''Pentagenia robusta'', the robust burrowing mayfly, is a recently extinct species of mayfly in the family

Ephemeridae Ephemeridae is a family of mayflies with about 150 described species found throughout the world except Australia and Oceania. These are generally quite large mayflies (up to 35 mm) with either two or three very long tails. Many species have ...

. It was

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found else ...

to the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territori ...

, found in the states

Indiana Indiana () is a U.S. state in the Midwestern United States. It is the 38th-largest by area and the 17th-most populous of the 50 States. Its capital and largest city is Indianapolis. Indiana was admitted to the United States as the 19th s ...

Kentucky Kentucky ( , ), officially the Commonwealth of Kentucky, is a state in the Southeastern region of the United States and one of the states of the Upper South. It borders Illinois, Indiana, and Ohio to the north; West Virginia and Virginia ...

, and

Ohio Ohio () is a state in the Midwestern region of the United States. Of the fifty U.S. states, it is the 34th-largest by area, and with a population of nearly 11.8 million, is the seventh-most populous and tenth-most densely populated. The sta ...

. 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 {{mayfly-stub