Olsson, A. A., 1932. Contributions to the Tertiary Paleontology of Northern Peru: Part 5, The Peruvian Miocene. Bulletins of American Paleontology, 19 (68 ).
New Species-Group Names:
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sophus Olsson, 1932. p. 154. pl. 16. f. 6. 8-9.
- spiekeri Olsson, 1932. p. 153. pl. 16. f. 5. 7.