considered a valid species from Argentina:
Austrolebias robustus (Guenther, 1883)

type locality:
Argentina, Province of Buenos Aires, La Plata, within 10 mi. of San Antonio. Holotype: BMNH 1879.6.28.12

type locality redefined by Calviño (2003):
temporary pools 2 km from Estancia “Los Yngleses”, 16 km (~ 10 miles) from Cape San Antonio; aprox. 36,480°S 56,820°W

remarks:
Austrolebias robustus was considered a synonym of A. bellotti by some authors and of Megalebias elongatus by others. The below listed authors consider the species as valid. Calviño redefined the type locality.

published in:
Calviño, P. (2003):
Redescrubiendo Austrolebias robustus (Günther, 1883).
Boletín del Killi Club Argentino – Special Edition 1; 15 pp.

Costa, W.J.E.M. (2002):
Monophyly and phylogenetic relationships of the neotropical annual fish genera Austrolebias and Megalebias (Cyprinodontiformes: Rivulidae).
Copeia 2002 (4): 916-927