Fig. 22. Lower right pm. 3-m.
1—natural size,
after Ameghino.
The species is the only one known of the genus, and its features are those of the genus. The following measurements indicate the size, lower pm. 3 to m. 1, 25 mm.; height of the mandible under molar 1 is 12 mm.
Proadianthus Ameghino
Proadianthus Amegh., 1897, Bol. Inst. Geog. Argen., t. 18, p. 455.
This genus is known only by the last two premolars of the lower jaw, which are compressed and moderately high. The two crescents are markedly separated by a cleft from the external side of the tooth, opposite to which is a high denticle, made by the fusion of the two ends of the crescents where they come together.
Proadianthus excavatus Ameghino
Fig. 23. Lower right
pm. 3 and 4—
natural size,
after Ameghino.
P. excavatus Amegh., loc. cit. above.