<Li> Pecatonica River mayfly, Acanthometropus pecatonica, Unknown, USA </Li> <Li> Rocky Mountain locust, Melanoplus spretus, 1902, Great Plains, Canada and USA </Li> <Li> Robert's stonefly, Alloperla roberti, Unknown, USA </Li> <Li> Robust burrowing mayfly, Pentagenia robusta, Unknown, Ohio River Area </Li>

Animals that have gone extinct in the us