Ameghino has suggested that the genus was related to ducks, but with the more complete material it seems, in general build, much closer to the aberrant land birds of the Tertiary of South America, Pelecyornis and Phororhacus; and I am not in position to say what their derivation may have been.
Beside the above species there are several more or less complete but isolated bones indicating the presence of other and much smaller birds. I figure such a femur natural size.
Footnotes:
[1] Anal. Mus. Nac. Buenos Aires, ser. 3, t. 8, p. 99.
[2] Bul. Soc. Geol. France, ser. 4, t. 3, 1903, p. 468.
[3] Formations Sedimentaires, p. 498, Anal. Mus. Nac. Buenos Aires, ser. 3, t. 8.
[4] Neues Jarhbuch fur Mineralogie. bd. 21, p. 193.
[5] Princeton Expeditions Reports, vol. 4, p. 303.
[6] Princeton Expeditions to Patagonia, vol. 3, p. 310, 1905-11.
[7] History of Mammals, p. 127, 1896.