 All remains except one Early Pleistocene partial skeleton from the Leisey Shell Pit near Charlotte Harbor, Florida (which may represent a different species or a subspecies) date from the Late Pleistocene, with the youngest remains dating from the Pleistocene-Holocene boundary.Its generic name means "monster bird".Another form, ""Teratornis" olsoni", was described from the Pleistocene of Cuba, but its affinities are not completely resolved; it might not be a teratorn, but has also been placed in its own genus, "Oscaravis".