In what will likely be considered one of the biggest (literally) zoological discoveries of the 21st century, scientists today announced they have discovered a new species of tapir in Brazil and Colombia. The new mammal, hidden from science but known to local indigenous tribes, is actually one of the biggest animals on the continent, although it's still the smallest living tapir. Described in the Journal of Mammology, the scientists have named the new tapir Tapirus kabomani after the name for "tapir" in the local Paumari language: "Arabo kabomani."

Tapirus kabomani, or the Kobomani tapir, is the fifth tapir found in the world and the first to be discovered since 1865. It is also the first mammal in the order Perissodactyla (which includes tapirs, rhinos, and horses) found in over a hundred years. Moreover, this is the largest land mammal to be uncovered in decades: in 1992 scientists discovered the saola in Vietnam and Cambodia, a rainforest bovine that is about the same size as the new tapir.

Found inhabiting open grasslands and forests in the southwest Amazon (the Brazilian states of Rondônia and Amazonas, as well as the Colombian department of Amazonas), the new species is regularly hunted by the Karitiana tribe who call it the "little black tapir." The new species is most similar to the Brazilian tapir (Tapirus terrestris), but sports darker hair and is significantly smaller: while a Brazilian tapir can weigh up to 320 kilograms (710 pounds), the Kabomani weighs-in around 110 kilograms (240 pounds). Given its relatively small size it likely won't be long till conservationists christen it the pygmy or dwarf tapir. It also has shorter legs, a distinctly-shaped skull, and a less prominent crest.

"[Indigenous people] traditionally reported seeing what they called 'a different kind of anta [tapir in Portuguese].' However, the scientific community has never paid much attention to the fact, stating that it was always the same Tapirus terrestris," explains lead author Mario Cozzuol, the paleontologist who first started investigating the new species ten years ago. "They did not give value to local knowledge and thought the locals were wrong. Knowledge of the local community needs to be taken into account and that's what we did in our study, which culminated in the discovery of a new species to science."

Cozzuol first found evidence of the new species a decade ago while looking at tapir skulls, which were markedly different than any other. Researchers then collected genetic material and tapir specimens from local hunters and the Karitiana Indians. Extensive research into both the tapir's physical appearance (morphology) and its genetics proved that the researchers were indeed dealing with an as-yet-undescribed species of megafauna. Amazingly, this new species of tapir was actually hunted by Theodore Roosevelt in 1912 with a specimen from his exploits still resting in the American Museum of Natural History in New York to this day. At the time of his hunt, Roosevelt wrote that the local hunters called the tapir a "distinct kind."

"[Indigenous people] were essential," co-author Fabrício R. Santos told mongabay.com, "particularly because they know about this 'variety' for decades, if not, centuries, and the hunters can precisely differentiate both species, because all of skulls they provide us matched our morphometric and DNA analyses."

Tapirs first appeared around 50 million years ago in the Eocene and are considered living fossils because they haven't changed much since then. They are easily identifiable by their massive size and their distinct, impressively-flexible proboscis, which the animal employs to grasp vegetation. Despite their bulk, tapirs are generally considered shy and elusive and are mostly active at night. They are also excellent swimmers and despite reputations in some countries for being slow (the name for tapir in Portuguese translates loosely to "jackass"), they are in fact quite intelligent, charismatic animals. Tapirs first evolved in North America and then migrated to Asia, South America, and even Europe in a tapir evolutionary-extravaganza before many species died out. Today, five species remain: four are found in Central and South America (the Brazilian tapir, mountain tapir, Baird's tapir, and the new Kabomani) while one species survives in Asia (the Malayan tapir).

The genetic research shows that the Kabomani tapir separated from its closest relative, the Brazilian, around 300,000 years ago. This means by the time humans first arrived in South America, the Kabomani tapir had long been separated from its relatives, although Brazilian tapirs and the Kabomani still share some of the same habitat today. The species is most common in the upper Madeira River where both forest and savanna habitat are present. When one of these ecosystems begins to dominate, however, the species becomes rarer. The scientists hypothesize in their paper that the species may have evolved "during dry periods of the Pleistocene, associated with forest fragmentation."

Moreover, the extensive genetic research undertaken by the scientists shows that the Brazilian tapir and the mountain tapir (Tapirus pinchaque) are quite closely related (more closely than the Kabomani tapir), which could mean a recent break between the two species with mountain tapirs quickly evolving to the high-altitude Andean cloud forests or something even more surprising.

"There may be another species inside what we call Tapirus terrestris, particularly the individuals found in the Amazon of Ecuador, and northern Peru," says Santos.

As megafauna, tapirs have been hunted by humans for thousands of years and still play a very important role in many indigenous tribes, both as food prey and in mythologies. In addition, these large animals are vital to the ecosystems they inhabit.

"As seed predators and dispersers, they have key roles in the dynamics of rain forests, Cerrado, Pantanal, and high mountain ecosystems," the scientists write in the paper.

All of the world's tapir species are currently listed as threatened with extinction due to overhunting and habitat destruction, and the scientists believe the Kabomani will be no different. In fact, given its scarcity and possibly smaller habitat than other tapirs, it could be hugely imperiled.

"[The Brazilian tapir] is considered Vulnerable by the IUCN, it lives in most of biomes of South America, and Tapirus kabomani was only found in Amazon areas with open grasslands. Because the new species is scarce, and more restricted in their local habitat, it should be much more threatened than the common tapir," notes Santos.

Moreover, the region of the Amazon where the tapir was discovered is facing heavy human pressures, including two large dams and massive road-building projects, in addition to high deforestation rates.

"Southwestern Amazonia is currently undergoing intense landscape modification by deforestation and increasing human population. The region is likely threatened more by global warming than are other South American regions and it is considered a biodiversity hot spot with undocumented species richness," the researchers write.

Now that the new tapir has finally been revealed to the global public, scientists and conservationists have their work cut out for them.

"Our next stage of research is to determine the actual distribution of occurrence and conservation status of the new species," says co-author Flávio Rodrigues, professor of ecology at UFMG. In fact, scientists suspect the new species may also be found in the Guiana Shield in the eastern Amazon, according to photographs and local knowledge from both Brazil and French Guiana.

The discovery of this new megafauna—so long-hidden to science—proves the invaluable contribution that indigenous people can make it science, if only they are more regularly consulted and respected, according to the researchers. It also proves once again that the natural world remains full of surprises.