When Dr. Eaton first examined the bone fragments he was surprised to find among them the bone of a horse. Unfortunately a careful examination of the photographs taken in Cuzco of all the fragments which were excavated by us on July 11th failed to reveal this particular bone. Dr. Bowman, upon being questioned, said that he had dug out one or two more bones in the cliff adjoining our excavation of July 11th and had added these to the original lot. Presumably this horse bone was one which he had added when the bones were packed. It did not worry him, however, and so sure was he of his interpretation of the gravel beds that he declared he did not care if we had found the bone of a Percheron stallion, he was sure that the age of the vertebrate remains might be “provisionally estimated at 20,000 to 40,000 years,” until further studies could be made of the geology of the surrounding territory. In an article on the buried wall, Dr. Bowman came to the conclusion that “the wall is pre-Inca, that its relations to alluvial deposits which cover it indicate its erection before the alluvial slope in which it lies buried was formed, and that it represents the earliest type of architecture at present known in the Cuzco basin.”
Dr. Eaton’s study of the bones brought out the fact that eight of them were fragments of human bones representing at least three individuals, four were fragments of llama bones, one of the bone of a dog, and three were “bovine remains.” The human remains agreed “in all essential respects” with the bones of modern Quichuas. Llama and dog might all have belonged to Inca, or even more recent times, but the bovine remains presented considerable difficulty. The three fragments were from bones which “are among the least characteristic parts of the skeleton.” That which was of greatest interest was the fragment of a first rib, resembling the first rib of the extinct bison. Since this fragmentary bovine rib was of a form apparently characteristic of bisons and not seen in the domestic cattle of the United States, Dr. Eaton felt that it could not be denied “that the material examined suggests the possibility that some species of bison is here represented, yet it would hardly be in accordance with conservative methods to differentiate bison from domestic cattle solely by characters obtained from a study of the first ribs of a small number of individuals.” Although staunchly supporting his theory of the age of the vertebrate remains, Dr. Bowman in his report on their geological relations admitted that the weakness of his case lay in the fact that the bovine remains were not sharply differentiated from the bones of modern cattle, and also in the possibility that “the bluff in which the bones were found may be faced by younger gravel and that the bones were found in a gravel veneer deposited during later periods of partial valley filling, ... although it still seems very unlikely.”