not a species from Argentina:
Amaralia hypsiura (Kner, 1855)

López et al. (2003) give a record of Amaralia hypsiura (sub A. hypsiurus) from Argentina referring to the only known argentinean specimen from río San Javier in Santa Fé province. Ferriz & Gómez (2002) provide information about a second argentinean specimen from the lower río Paraguay.
Friel (1994, 2003) indicates an undescribed species from the Paraguay-Paraná-system and restricts the distribution of A. hypsiura to the Amazon basin (2003). Friel (2000) also proposes the working name Amaralia ‘oviraptor’ for a new species, unavailable until published in the sense of the ICNZ, and without confirming that this name refers to the species from the Río de la Plata basin.
As long as the new species is not formally described, records from localities in Argentina should be referred to as Amaralia sp.

published in:
Ferriz, R. & S.E. Gómez (2002):
Primer registro de Amaralia hypsiura (Pisces, Aspredinidae) para la baja cuenca del río Paraguay y apuntes a su morfometría.
Historia Natural (Segunda Serie) 1 (1): 1-3

Friel, J.P. (1994):
A phylogenetic study of the neotropical banjo catfishes (Teleostei: Siluriformes: Aspredinidae).
Unpublished Ph.D. Thesis, Duke University, 256 p.

Friel, J.P. (2003):
Family Aspredinidae (Banjo catfishes). pp. 261-267
In: Reis, R.E., Kullander, S.O. & Ferraris, C.J. Jr (eds.)
Check list of the freshwater Fishes of South and Central America.
Edipucrs, Porto Alegre, 729 pp.