The first clue was the fur.

While studying silky anteaters in Brazil, biologist Flávia Miranda "began to see differences between the colors of the population of the Amazon and the Atlantic forest," she recalls.

There was just one recognized species—Cyclopes didactylus—but she wondered if these little-known tree-dwellers might qualify as two separate species.

Miranda, of Brazil's Federal University of Minas Gerais, and colleagues went on 10 expeditions in Brazil and Suriname in search of silky anteaters over a decade, as well as scoured natural history museums for additional biological samples. (Read how new Amazon species are discovered every other day.)

By the end, the team wound up with DNA samples from 33 wild anteaters and anatomical information collected from an additional 280 museum specimens.

Her initial hunch was right: The two groups of silky anteaters were different. In fact, there may be up to seven different types of silky anteaters, according to her study, published December 11 in the Zoological Journal of the Linnean Society.

"This is a good example of the startling results that can emerge when a widespread animal that has hardly ever been studied in any detail is examined with modern techniques for the first time," says Kristofer Helgen, a mammalogist at the University of Adelaide in Australia. "I won't be surprised if future research on these beautiful animals shows even more overlooked species," he says.

View Images Researchers take a blood sample from a wild silky anteater. They drew DNA samples from 33 wild anteaters in all. Photograph Courtesy Karina Molina, Alexandre Martins and Flávia Miranda

Shy Tree-Dwellers

In 2005, Miranda learned that scientists were unsure whether silky anteaters even still lived in the northeastern Atlantic rain forest, inspiring her to study the enigmatic mammals. (Read more about the giant anteater.)

Her team's first challenge was figuring out how to capture them.

Just 20 inches long and nocturnal, they're the least studied of all the anteaters, mainly because they're so hard to find. Found throughout central and South America, silky anteaters also spend their lives hidden in the tree canopy, feeding mainly on ants.

Miranda and colleagues distributed flyers throughout Brazil's indigenous communities, asking them for their expertise in tracking, finding, and capturing the furry critters. "It took us two years to capture the first animal," she says.

Anteater vs. Termites A giant anteater gets its fill of termites before their tiny bites become overwhelming.

While some researchers had already proposed dividing silky anteaters into a set of subspecies, Miranda started from scratch, working from the assumption that only one species, Cyclopes didactylus, existed. In addition to the genetic material, the team relied on skull measurements and fur coloration as potential means of distinguishing each species. (Read about a "teddy bear" mammal discovered in South America.)

The genomic and anatomical analyses confirmed that four of the previously proposed subspecies were indeed distinct. The team then identified another three species that had never before been proposed, for a total of potentially seven different species.

View Images Researchers take detailed anatomical measurements of a wild silky anteater. By taking measurement data from a variety of anteaters, they were able to identify differences between species. Photograph Courtesy Karina Molina, Alexandre Martins and Flávia Miranda

"Just Beginning"

The International Union for Conservation of Nature classifies C. didactylus as a species of least concern, in part because it's so widely distributed.

But with the new splits in its family tree, it isn't clear how each new species is faring.

The researchers are now hard at work assessing threats to each newly described species so conservationists can better protect them. (See maps that show how global consumption affects wildlife.)

Miranda suspects that at least two of the new species are threatened with extinction, under pressure from deforestation due to mining and agriculture.