Could a ground sloth be living today?

What is the mapinguari?

It may sound like an exotic dish on a TV cooking show, but no.  It is, according to Brazilian ornithologist David Oren, a huge, prehistoric ground sloth that still breathes in the forested lands of the Amazon basin.  

In the 1990s, Dr. Oren’s fieldwork as the head of zoology at Emilo Goeldi Natural History Museum brought him in contact with many tales of the mapinguari.  South America’s pre-eminent finder of new mammals, Dr. Marc van Roosmalen, had also heard of the animal and was intrigued.

While some cryptozoologists think these tales refer to a huge primate, Oren was struck by the way descriptions of the red-haired beast corresponded with what we know of the mylodontid ground sloths.  There were several species of ground sloths in the Americas.  The largest, Eremotherium laurillardi, reached the size of a respectable elephant at around three tons.  Some South American species were definitely hunted by early humans and are believed to have been alive only 8,500 years ago.   Also in favor of a sloth identity: there’s no evidence for any primate remotely approaching the size of Homo sapiens in the New World, let alone the size of a ground sloth.

Features of the mapinguari reports which match some ground sloths include general size and appearance, tracks showing clawed toes pointed inward, and the color (samples of ground sloth skin, still flexible, have been found preserved in caves).    

According to the people of western Amazonia, the mapinguari is a shaggy animal weighing over 250 kg.  This would make it one of the smaller ground sloths, but it would still be the largest living mammal native to South America.  Oren believes the mapinguari is nocturnal and vegetarian.  It rears up to a height approaching six feet when startled and is supposedly accompanied by a stench which could gag a jaguar.   Whether the animal is still living or has gone extinct very in the last few years is a question Oren cannot answer, but proving either possibility would be a scientific coup.

In 1995, Oren launched his first expedition into the Brazilian rain forest in search of the mapinguari.   This seems an outlandish pursuit for a man with a Harvard doctorate, but Oren found the eyewitness accounts and eleven-inch tracks compelling.  He was also well aware of the publicity that would accompany the discovery of such a spectacular animal – publicity that would lead to increased protection for the hard-pressed rain forest.  He has devoted enormous effort to the project, persevering through several arduous expeditions and a growing thicket of skepticism from his colleagues.  He has also attracted some assistants.  One is writer Marcelo Volcato, who in 1999 located a new witness in the state of Matto Grosso who described a creature with long reddish hair, standing over five feet tall on its hind legs and smelling very bad.  The man was familiar with regular sloths and saw no resemblance, although his description resembles nothing else known in Brazil either. 

Folklore endows the mapinguari with the power to make people dizzy, and sometimes with a second “mouth” in its stomach: Oren suggests the latter is a scent gland that explains the former. 

Scientific opinion is split, with most of it against Oren.  Professor Paul Martin, an expert on megafaunal extinctions, is one of many who has said Oren is wasting his time.  “I’ll eat my share of sloth dung if this animal is alive,” he opined.  On the other hand, Dr. Glenn Shepard Jr., an anthropologist working with a tribe on the Peruvian stretch of the Amazon, heard tales of the animal but didn’t think much of them until a man who’d been to the natural history museum in the capitol of Lima said he’d seen the same animal on display there as a fossil. Shepard was taken aback on finding out this was a ground sloth.

Giant ground sloths, painted by Charles R. Knight (public domain)

Oren’s work has, at this point, led largely to disappointment despite talking to “a couple hundred” witnesses.  Hair and fecal samples he’s gathered have been identified as those of known animals. (I once talked by phone to an eminent mammologist focused on South America, Dr. Louise Emmons, who was skeptical of the mapinguari and told me concerning one of Oren’s reports, “I can’t believe he didn’t know tapir s--- when he saw it.”) 

Recent years haven’t added a great deal of information. Josh Gates and his Destination Truth team went to Brazil in 2008. They found some new witnesses and heard loud crashing noises, but didn’t get any hard evidence. Biologist Pat Spain took his Beast Hunter show there in 2011, and after earning the trust of a local tribe by passing a ritual involving gloves full of huge, stinging “bullet ants” that had him screaming in pain, was able to talk with numerous hunters who had seen the animal, but that was about it. However, it should be added that Spain was highly impressed by the certainty of the people he spoke with and came away thinking there was some kind of real animal involved.

While Oren has said, “I’ll be the first one to admit the whole idea is rather absurd,” he has also said, correctly, “I’m testing a scientific hypothesis that’s basically reasonable.  This isn’t the Loch Ness monster.”

The beast can’t be said to be disproved yet, not with 5 billion hectares of forest still left in the Amazon basin.  It is unlikely, and the results of 20+ years of work have been disappointing.  But this is one animal in the crypto-zoo that someone, someday, might trip over.  Just hope the giant creature doesn’t trip over you.  

Further Reading: 

Goering, Laurie.  1995.  “Expert says tree sloths have a monster cousin,” Columbus (Ohio) Dispatch, January 15.

Holloway, Marguerite.  1999.  “Beasts in the Mist,” Discover, September, p.58.

Holloway, Marguerite. 1993. "Living Legend," Scientific American, December, p.40.

Oren, David.  1993.  “Did ground sloths survive to Recent times in the Amazon region?”  Goeldiana Zoologia (19), (August 20).

Pearson, Stephanie.  1995.  “Load the Stun Gun, Pass the Old Spice,” Outside, November, p.34.

Rohter, Larry.  2007. “A Huge Amazon Monster Is Only a Myth. Or Is It?” New York Times, July 8.  

Spain, Pat. “Beast Hunter: Nightmare of the Amazon,” http://channel.nationalgeographic.com/wild/beast-hunter/episodes/nightmare-of-the-amazon/