The first published reference to the Minhocão appeared in the American Journal of Science in an article written by Auguste de Saint-Hilaire. In the article Saint-Hilaire stated several instances where a Minhocão was seen near fords of rivers. Some of these reports had a Minhocão snatching livestock and dragging them underwater! All of instances he reported took place in the Brazilian province of Goyaz. Saint-Hilaire also stated his belief that the name Minhocão is derived from the Portuguese word meaning earthworm, minhoca.
Publications regarding the Minhocão ceased until 1877, when zoologist Fritz Müller wrote an article on the beast for a German publication Zoologische Garten. Müller's article included new information on the Minhocão, including reports of huge mysterious trenches that were so big they'd divert rivers and destroy orchards. Unlike Saint-Hilaire's article, Müller's included actual sightings of the Minhocão. The following is of one of these sightings, which took place in the Paranà State in the 1840s:
A black woman going to draw water from a pool near a house one morning ... saw a short distance off an animal which she described as being as large as a house moving off along the ground. ... In the same district a young man saw a huge pine suddenly overturned ... he found the surrounding earth in movement, and an enormous worm-like black animal in the middle of it, about twenty-five meters long, and with two horns on its head.
Müller also mentioned a story told by Lebino José dos Santos who had heard tales of a dead Minhocão being found near Arapehy, Uruguay. According to the tale the creature was found lodged between two rocks, the reputed skin was said to be "as thick as the bark of a pine-tree" and armored with "scales like those of an armadillo". A sighting of a live Minhocão near Lages, Brazil in 1870 by Francisco de Amaral Varella, he said he:
... saw lying on the bank of the Rio das Caveiras a strange animal of gigantic size, nearly one meter in thickness, not very long, and with a snout like a pig, but whether it had legs or not he could not tell. ... whilst calling his neighbors to his assistance, it vanished, not without leaving palpable marks behind it in the shape of a trench ...
With the end of the 19th century also came the end of Minhocão sightings. There are still large mysterious trenches from time to time, but no actual sightings. Some researchers believe that the Minhocão, sadly, went extinct, while others think it is more likely that Minhocãos are still seen, but are thought to be giant anacondas and end up being reported as giant anacondas. There is still the question of what the Minhocãos could possibly be. Some researchers take into account that it is said to be a giant earthworm. There are giant earthworms, but these species don't grow over 12 feet and are only native to Australia. Also despite their large sizes, these giant earthworms are only about an inch thick. Another fact that may debunk the giant earthworm theory is that earthworms are not predators like some reports state the Minhocão may be.
Some researchers say that the Minhocão are surviving glyptodont, a large armadillo-like animal believed to have gone extinct in the Pleistocene. Researchers say that the glyptodont would be capable of digging the mysterious trenches and burrowing underground, it also had and armored shell over it's back. What is normally not mentioned about the glyptodont is that it was not a borrowing animal and it was probably not capable of doing so. There is also the fact that they do not fit any descriptions of the Minhocão.
Yet another theory goes on to say that the Minhocão is a lepidosiren (serpentine South American lungfish). If a lepidosiren were to grow to a large enough size it could explain the sightings of Minhocão near waterways. The large trenches could also be caused by a lepidosiren when it unburrows itself from the ground and returns to the rivers. One of the most likely theories of the Minhocão's identity was proposed by cryptozoologist Karl Shuker. He believes that the Minhocão may be a form of caecilian, a worm-like burrowing amphibian. Caecilians are native to South America and some fit the description and lifestyle of Minhocão perfectly, only in a smaller form. The largest of the caecilians only gets up to 5 feet. If one species does grow to enormous lengths then the Minhocão mystery would be solved.
The true identity of the Minhocão will remain hidden until one can be caught or good footage of it can be obtained. However it seems unlike that we will ever know the truth. Without a sighting of an actual animal in over a 130 years it may be extinct by now. Hopefully this is not the case and some day soon a living Minhocão will be discovered in the rainforests of South America.