As a consequence of the Mylodon Cave findings, another Patagonian beast became known, the Iemisch or Yemisch. It was first mentioned in Ameghino’s 1898 mylodon paper .
He said that the Tehuelche had informed his brother Carlos about a mysterious and aggressive creature, the Iemisch, which roamed Patagonia: Mysterious four legged massive beast, of a terrible and invulnerable appearance, whose body cannot be penetrated by missiles or brning branches. They call it Iemisch or "water tiger" and mentioning its name terrorizes them; when interrogated and asked for details, they become grim, drop their heads, turn mute or evade answering. He then went on to add that it was not a myth, but a real being, and that when his brother had sent him the skin of a mylodon he had included the following letter, which we quote fully below: At last I have managed to get from the Tehuelche Indians, some precise data on the famous Iemisch, which is not a myth or a ghost as we have thought, but something that truly exists.
I have seen an Indian who had a piece of Iemisch hide that has tiny bones embedded in it; which I am sending to you, similar to the fossilized ones we found in mylodon skeletons; and Hompen, another Tehuelche Indian, has told me how, while going by Senguer [River] in Santa Cruz, met a Iemisch on the road, that closed his way, and fought with it, killing it by hitting it with his bolas. According to them, it is amphibious and walks on land with the same ease as it swims in the water. It is now confined to the central Patagonia, in caves and protected areas along the shores of Colhue, Fontana [and] Buenos Aires lakes, and Senguer, Aysen and Huemules rivers, etc., but that according to tradition, they used to extend in other times to the north up to the Negro river, and on the south, according to what old Indians can remember it lived in all the lakes of the oriental foothills of the Andes up to the very Strait of Magellan.
About half a century ago , an Iemisch that was coming down the Santa Cruz River from the Andean lakes, landed on the northern shore of the river close to Pavón Island; the terrified Indians ran inland, and since then as a remembrance of this unexpected apparition, this abandoned place still today bears the name of "Iemisch-Aiken" (place or location of the Iemisch).
It is a creature of the night, and they say that it is so strong that it grabs on to horses with its claws dragging them into the water. According to the description that they gave me, it has a short head, large fangs and its external ears are lacking or rudimentary; short and flat feet (plantigrade) with three fingers on its front paws and four on the rear ones, joined by a natatory membrane and with formidable claws. The tail is long, depressed and prehensile. The body is covered with short, hard and rigid hairs, of a uniform brownish color. The size is said to be larger than that of a puma, but with shorter legs and a much thicker body. Thus Ameghino contended that his Neomylodon and Iemsich were the same creature. Could he have been correct in his assumption?
Ameghino’s paper was soon quoted by Florencio de Basaldúa -interim governor of the Patagonian Territory of Chubut- in the article Monstruos Argentinos(Argentine Monsters), published in the Buenos Aires magazine Caras y Caretas on May 13, 1899. In it Ameghino is cited as stating that he had got a Iemisch hide from “the shores of lake Colhue Huapi, hunted and killed by the Indian Hompen, that lives there”.
It should be noted that Senguer River flows into Colhue Huapi Lake, where as recently as 2001, there have been sightings of a strange bulky aquatic being
Real or made up?
Surprisingly, before Ameghino, not one single Patagonian explorer had ever mentioned the Iemisch; and we have no other records of any Aonikenk myths referring to an animal named Iemisch.
To be fair, there are references to Aonikenk monsters such as Goshg-e, which though not described as aquatic, was very similar to the Iemisch in its dreadful size and aggressiveness.
For this reason, Ameghino’s Iemisch was quickly under attack by other scientists, so he was forced to defended himself. In a letter dated April 4th, 1901 to German-Brazilian Dr. Herman von Ihering he said that “the references to Jemisch [sic] are exploited in ill faith. I have not described the Neomylodon by references but from the mentioned bones […] and simply referred the descriptions of a large mammal that inhabits the Patagonian lakes […] if these descriptions are not reliable, the blame is not mine […] Probably there is not only one mysterious mammal living in Patagonia, but several”.
In his letter he enclosed a clipping of the Buenos Aires daily La Nación, in which his witnesses were not voluble natives, but supposedly more reliable “white people”. Regarding the article, Ameghino noted that “Steinkanpen was accompanied by two cow hands by the name Montesinos who live in Chubut and two sons, one aged 18, the other 16. The five of them saw the monster. Mr. Zubizarreta was accompanied by several soldiers. I have spoken to others who have shot at Jemish [sic] from a distance of 3 meters [9 ft.]”.
Shortly before, on March 3rd, 1901, his brother had written to him cheerfully “it seems that the mylodon has been seen this time in the mountains by the Gallegos River by neighbors of that place, and it is not improbable that any moment we may get the news that it has been hunted. This time it seems to me that it is true and serious”.
De Basaldúa was also on the look out, and in July 1901 wrote to Florencio that he was corroborating “very important news on the Neomylodon Listai”.
What came of these leads no one knows. There is no further correspondence on the matter, Neomylodon and Iemisch vanished.
During his 1900 Patagonian expedition, French naturalist André Tournouer saw a creature emerge in the middle of a stream, its round head was the size of that of a large puma, with dark fur. Its eyes were encircled with light yellow hair. It lacked external ears.
He shot at it and the animal quickly disappeared under the water. He later came across some large cat-like tracks in the sand.
His native guide seemed very frightened and told him that beast and tracks belonged to the mysterious Hymché.
Tournouer was certain that it was not a Neomylodon and believed that it was a carnivore.