Eucallornis Ameghino, 1901 † (original description)
Eucetites Ameghino, 1901 † (original description)
Palaepanorthus Ameghino, 1901 † (original description)
Parabderites Ameghino, 1901 † accepted as Parabderites Ameghino, 1902 † (original description)
Prepneornis Ameghino, 1901 † (original description)
Prolicaphrium Ameghino, 1901 † (original description)
Proschismotherium Ameghino, 1901 † accepted as Proschismotherium Ameghino, 1902 † (original description)
Prospaniomys Ameghino, 1901 † accepted as Prospaniomys Ameghino, 1902 † (original description)
Protacaremys Ameghino, 1901 † accepted as Protacaremys Ameghino, 1902 † (original description)
Protadelphomys Ameghino, 1901 † accepted as Protadelphomys Ameghino, 1902 † (original description)
Prothoatherium Ameghino, 1901, nom. nud. † accepted as Prothoatherium Ameghino, 1901 † (original description)
Pseudoborhyaena Ameghino, 1901 † accepted as Pseudoborhyaena Ameghino, 1902 † (original description)
Pseudostegotherium Ameghino, 1901 † accepted as Pseudostegotherium Ameghino, 1902 † (original description)
Teracophrys Ameghino, 1901 † (original description)