A scientific expedition to La Paz, Bolivia, discovered the cloud forest in the Bolivian Andes was hiding 20 species previously unknown to science. Among the bumper crop of new species are the mountain fer-de-lance viper, the Bolivian flag snake, the lilliputian frog, as well as four shiny new butterfly species. Co-led by Trond Larsen, director of Conservation International’s Rapid Assessment Program (RAP) and Claudia Cortez, head of Conservation and Wildlife Management for the Municipal Government of La Paz, the research saw 17 scientists trek to the Chawi Grande, a locality belonging to the Hualylipaya community of La Paz, an area considered the heart of the region and known as the Zongo Valley.
Here are some of the expedition’s most fascinating findings:

mountain fer-de-lance
This venomous pit viper is a new species to science after being discovered during the expedition. Like all pit vipers, it has a sixth sense in the form of two infrared-detecting organs on its head known as pits, which enables it to sense passing prey.

LILLIPUTIAN FROG
This tiny frog is just 10 millimeters (0.4 inches) in length making it the smallest of the Andes’ amphibians. It lives mostly below ground moving around in a system of tunnels, which explains why they’ve gone so long without being discovered. The researchers tracked them by trying to find the source of their frequent calls and eventually spotted the miniature amphibians among the moss.

Bolivian flag snake
This small, slender snake is quite the patriot, sporting the yellow and green colors found on Bolivia’s national flag. It was found at the highest elevation surveyed in the expedition, slithering among the dense undergrowth of a miniature forest at the summit.

New butterflies
Using a long-handled net to reach the forest canopy, researchers found four new species of butterfly including three new species of metalmark butterfly and a new satyr butterfly.

New orchids
The expedition revealed that the forest wasn’t just home to previously unknown insect species but also a new plant pretending to be an insect. The Adder’s mouth orchid has flower parts that mimic the shape of an insect, which the researchers suggest benefits the plant by luring in unwitting pollinators. The expedition also uncovered a species of Myoxanthus orchid whose flowers bloom at the base of its leaves, and a vibrant cup orchid with purple and yellow flowers.

Long lost species
The expedition didn’t just find new species but also known species that hadn’t been seen for decades. These included the devil-eyed frog, last seen 20 years ago, and another species of satyr butterfly that had been MIA for 98 years.

The survey was carried out to gather data that could inform a sustainable development plan for rural areas of La Paz, 78 percent of which falls within the Zongo. The municipality wishes to preserve the area’s unique and evidently thriving biodiversity and conserve its ecosystems while still moving forward with developing the area.
“These discoveries are the result of 14 days of intense fieldwork spread across the rugged terrain, misty cloud forests, and cascading waterfalls of the Zongo – a truly beautiful and diverse landscape,” said Larsen in a press release. “The remarkable rediscovery of species once thought extinct, especially so close to the city of La Paz, illustrates how sustainable development that embraces conservation of nature can ensure long-term protection of biodiversity as well as the benefits ecosystems provide to people. This area has become a safe haven for amphibians, reptiles, butterflies, and plants that haven’t been found anywhere else on Earth.”