Identifying the... Mapinguary

Megatherium reconstruction.
Image credit Sloth Sanctuary.

Given the evidence and general consensus amongst cryptozoologists, it seems unthinkable to characterise the Mapinguary as anything other than a relict ground sloth. Even so, there are theories that it is actually a type of large primate - and even it it isn't, there are still dozens of different ground sloths. The Mapinguary, if a sloth, can only be a descendant of one.

Original legendary accounts described an animal which was really little like an ape or a sloth: a towering beast with a single eye and a mouth in its stomach. More recent sightings describe - if you'll excuse the text copied directly from David Oren's 2001 paper - an animal approximately two metres tall when standing upright; a very strong, unpleasant smell (most say that it’s just the worst odor they ever smelled, although others describe the stench as a mixture of feces with rotting fl esh); extremely heavy and powerful build; capable of breaking thick roots with its footsteps; claws like an anteaters; long coarse fur that is either reddish, blackish or brownish in color; a muzzle that looks like a burro’s or horse’s, though shorter; four large canine-like teeth; the ability to locomote on all fours and bipedally, although the bipedal gait is not agile; footprints that are roundish (quadrupedal gait) or like people’s, but with only four toes (bipedal gait); and extremely loud, roaring vocalisations and/or vocalisations similar to a human calling loudly, but with a growl at the end.

People who claim to have shot one say that the animal was taken down by a large slug fired directly at the head, although one man claimed to have unloaded his revovler directly into the animals chest.

This description matches a ground sloth rather perfectly, and doesn't seem to really fit with a primate of any sort. In addition: one witness, Geovaldo, also identified an image of a ground sloth as what he saw and shot; some Indians told Glenn Shepard, Jr. that a ground sloth statue was a Mapinguary; and Pat Spain blasted a slowed-down sloth call into the rainforest and got a response.

So first, we'll look at the sloths.

Scientists have decided to classify the sloths in a number of groups. Bradyopdidae, the three toed sloths; Megalonychidae, the two toed sloths and some ground sloths; Megatheriidae; Nothrotheriidae; and Mylodontidae. The first two groups, which are composed entirely of either tree sloths or North American ground sloths like the Jefferson's ground sloth (Megalonyx jeffersonii), are not relevant to the Mapinguary (probably not, anyway - see below). The Megatheriidae is mostly out of the question, as that is the family of the "great beast", Megatherium americanum itself, an animal vastly larger than the Mapinguary is said to be. It's also difficult to believe that such a large animal could thrive in a place as dense as the Amazon.

Almost all of the ground sloths went extinct very recently. They reached their pinnacle during the later stages of the Pleistocene, with many going extinct as man became more prolific about 12,000 years ago. However, like most animals of the Ice Age, most of them crossed the 11,000-10,000 years boundary and made it into the Holocene, the modern age. A good deal of them are believed to have survived even longer than this, beating sabre-toothed cats and short-faced bears by making it nearly into historic times. This collection of late-surviving ground sloths includes smaller island forms, most mylodonts, and the ever-hardy Megatherium, which doesn't really have a good reason for being extinct - models show that it would be unaffected by climate change, and it's difficult to imagine how primitive humans could manage to harm such a big animal.

(1) Megatherium at London (2) Glossotherium at London (3) Megatherium at Madrid (4)
London Megatherium closeup
Image credits Wikipedia.

The Mylodontidae, which includes the Harlan's ground sloth (Paramylodon harlani), Glostotherium, and Darwin's ground sloth (Mylodon darwinii), has traditionally been considered the most likely family to which the Mapinguary would belong to. Most genera of this family were about the size of a bull, with osteoderms beneath their skin, which would make them bulletproof, like the Mapinguary. Mylodon is usually named as the culprit amongst these animals: however, a recent study found that Glossotherium had had large ear ossicles, which means it would have communicated vocally, like the Mapinguary. Glossotherium is also believed to have been capable of surviving on less nutritional vegetation than most other ground sloths. Among mylodonts, this makes Glostotherium the most likely culprit.

However, in his 2001 paper, Oren went back on this, claiming that the Mapinguary cannot be a mylodont, since the mylodonts did not have the right teeth. He instead suggests it must be a megalonychid: however, the only known genera in that family - besides the North American Jefferson's ground sloth and the living sloths - are fairly small, arboreal animals from the montane woodlands of the Central American Antilles islands, which are known to have survived into historic times. However, they are not the right size to be the Mapinguary.

It must also be noted that the ground sloth image identified by Geovaldo as the Mapinguary was a reconstruction of a Jefferson's ground sloth, of the Megalonychidae: however, Geovaldo did say that the animal he saw was slightly different to the reconstruction - his animal had bigger claws, for one thing.

The Jefferson's ground sloth reconstruction identified by Geovaldo.
Image credit Don Glut.

This leaves Nothrotheriidae. The Nothrotheriidae, closely related to the Mgeatheriidae, contains few genera: the most notable are probably the Shasta ground sloth (Nothrotheriops shastensis), the marine Thalassocnus (an animal which provides an excellent snapshot of evolution in action), and Nothrotherium (amidst all this name-dropping, I'd like to say that, in my opinion, a good common name for the Mapinguary, should it be discovered, would be Oren's ground sloth).

The Shasta ground sloth can probably be written off, since it made its home in the Mojave Desert. Thalassocnus was a marine animal from Peru, not at all consistent with the Mapinguary.

Nothrotherium, however, is more promising. The fossils of this large ground sloth are known only from Brazil, so it would not take a stretch of the imagination to believe it could have thrived in the Amazon Rainforest, which has been around since the Early Palaeocene.

So, amongst the ground sloths, there are three likely culprits: Glostotherium, Nothrotherium, or an unknown megalonychid (it is not out of the question to say that the Jefferson's ground sloth itself made its way to South America in historic times).

As a note, there were actually a number of megalonychids living in South America, including one, Proplatyarthrus, which is believed to have survived into the Early Holocene. Wikipedia is a flawed website, and only lists a few genera.

Of course, when discussing identities of cryptids in terms of families and genera, one must remember the words of Heuvelmans, in On the Track: "in nature, there are only individuals" - families and species are merely our own illusions, created by us to increase our understanding.

Before we move on to the primate theory, a number of other edentate identifications have been put forth to explain the Mapinguary. A giant anteater is the most common theory: most cryptozoologists use the anteaters general pacifism as an argument against this theory, but an even better argument is that eyewitnesses do not describe the Mapinguary as having an anteater-like face. A regular sloth has also been blamed as the culprit. Almost all eyewitnesses are experienced native hunters, so it is difficult to believe that they could mistake a known animal for a supposedly mythical one. Case in point: some researchers believe that the description of the Mapinguary is more consistent with a bear than a ground sloth. However, when asked about this similarity, native Indians expressed surprise and affirmed that they knew the difference between a bear and the Mapinguary (Oren, 2001). Geovaldo also perfectly passed an "animal identity parade" done by Pat Spain.

Next, on to the more questionable theory of the Mapinguary representing a giant ape, like the De Loys' ape (Ameranthropoides loysi).

De Loys' ape (Ameranthropoides loysi). Despite most
zoologists claiming this animal to be a dead spider
monkey, it clearly shows a new, distinct, and large species.

That the Mapinguary is an unidentified primate is a theory which has been supported by Bernard Heuvelmans himself, in On the Track of Unknown Animals. However, this book was published long before Oren was the first to suggest that the Mapinguary represents a sloth.

The most common argument for the ape theory, and against the sloth theory, is that ground sloths had long tails: the Mapinguary does not. However, the tails were not outlandishly long, and most Mapinguary encounters occur from the front, where a tail would not even be seen.

Undoubtedly, some sightings and vocal encounters with the Mapinguary can be explained by anteaters, tree sloths and, yes, unidentified apes - but the majority of eyewitnesses are very clear about what they saw. A giant ground sloth.

Read more about the Mapinguary.