Phororhacus Ameghino

This is a group of large land birds, comparable in size to the great moas of New Zealand which apparently arose, flourished, and died out in South America. In the Santa Cruz they were abundant, the best known form being P. inflatus, a bird some six feet high; while the largest, P. longissimus, had a head nearly twice as long and limb bones half again as large as this species; so that it represented a bird nine to ten feet high. Previously but one specimen of this type, a part of a mandible, has been found in the Deseado beds. We were fortunate enough to find the greater part of a femur, indicating a bird equal to the largest of those in the Santa Cruz. There are also toe bones of Phororachus of a size about the same as P. inflatus.

A host of names, generic and specific, have been given to the individual bones of the birds of this type, but Ameghino, in studying the birds of the Santa Cruz, brought them all together under the single genus Phororhacus. (See Bol. Inst. Geog. Argen., 1895, t. 15.) Referring to the single bone in the Deseado, however, he gave it a new generic name Physornis, which differs from Phororhacus only in the lower jaw being more convex, but should stand until better material has been found to establish whether it differs enough to be entitled to generic independence.