The buffy-tufted-ear marmoset is a disgruntled-looking creature. It’s got thick black fur and a face that makes it look like it’s perpetually smelling a bad odor.

It’s also in deep trouble.

Once, in the jungles of Brazil, the marmoset was living large. Belonging to a “family of tiny New World monkeys,” it lived in coastal forests, residing almost exclusively in trees and dining on insects.

But development encroached upon its world. There was “extensive habitat destruction” due to “a tremendous increase in human population and widespread, largely uncontrolled forest destruction” for crop cultivation and cattle. By 1982, according to this book featuring the mammal, forest destruction had “already destroyed most of its habitat.”

The story of the buffy-tufted-ear marmoset is part of the story of a great extinction, according to a study published Thursday in the journal Science. Species of plants and animals are dying out at least 1,000 times faster than before the advent of the human species, and if things don’t turn around, it may get a whole lot worse, researchers said.

“We are on the verge of the sixth great extinction,” Stuart Pimm, a professor at Duke University who lead a team of nine international scientists, told the Associated Press. “Whether we avoid it or not will depend on our actions.”

Previous mass extinctions are often associated with a meteor strike, one of which likely killed off the dinosaurs 66 million years ago. Another extinction, called the Great Dying, offed 90 percent of the world’s species 250 million years ago — though as The Washington Post’s Fred Barbash pointed out, that one may have been caused by a microbe.

This study focused on contemporary rates of extinction and used databases such as the Red List of Threatened Species. Researchers compared today’s rates with those before humans arrived. And today’s, according to the AP, are 10 times faster than scientists had earlier believed.

“Recent studies clarify where the most vulnerable species live, where and how humanity changes the planet, and how that drives extinctions,’ the study said. “We assess key statistics about species, their distribution, and their status.” Many land-based species are distributed across terrains smaller than the state of Delaware, Pimm said in this Duke University press release.

Such species are “geographically concentrated and are disproportionately likely to be threatened or already extinct,” the study said. “Future rates depend on many factors and are poised to increase. Although there has been rapid progress in developing protected areas, such efforts are not ecologically representative, nor do they optimally protect biodiversity.”

The number one threat to the world’s many species: habitat loss. It is becoming increasingly difficult, researchers said, to find any speck of planet that hasn’t been either altered or built upon by humans. Complicating efforts: There are so many species no one knows of. “Most species remain unknown to science, and they likely face greater threats than the ones we do know,” Pimm said in the press release.

According to the Associated Press, the study was hailed as a “landmark” work by outside experts. “If we don’t do anything, this will go the way of the dinosaurs,” said Dalhousie University marine biologist Boris Worm, who lauded the study though wasn’t a part of it.

There was reason for hope, however. Smart phones and other crowd-sourcing apps “are making it easier to collect data on species,” Pimm said. “When combined with data on land-use change and the species observations of millions of amateur citizen scientists, technology is increasingly allowing scientists and policymakers to more closely monitor the planet’s biodiversity and threats to it.”

He said such technological precision may allow researchers to target specific species in trouble. “For our success to continue, however,” he said. “We need to support the expansion of these technologies and the development of even more powerful technologies to come.”