[4] The so-called "tiger stingray" has sometimes been misidentified as P. menchacai (a synonym of P. falkneri), but it is a separate species that only was scientifically described as P. tigrina in 2011.

[2] The species name is in honor of British Jesuit Tomas Falkner (1707-1784), (also spelled Thomas Falconer), for his apostolic and scientific work in Argentina in the 18th-century.

[6] This species has a disjunct distribution with the best-known population found throughout much of the Paraná—Paraguay River basin in southern Brazil, Paraguay, Uruguay and northeastern Argentina.

[4] Initially it did not occur in the upper Paraná basin above the Guaíra Falls, but these disappeared after the construction of the Itaipu Dam, allowing this species (and several others) to spread.

[7] The other main distribution of P. falkneri is in the upper Amazon Basin: Madre de Díos, Guaporé, Beni, Marañón and Solimões Rivers in Bolivia, eastern Peru and western Brazil.