Amphibians are among the planet’s most charismatic ambassadors for imperiled biodiversity.

Faced with a variety of threats, from disease to habitat loss, about half of the world’s roughly 7,000 species of amphibian are threatened with extinction—and more than 250 of those species haven’t been seen since the turn of this century.

That’s why Conservation International scientist Dr. Robin Moore launched a six-month, 21-country effort to search for frogs, toads and salamanders that hadn’t been documented in decades. From Borneo to Brazil, Colombia to Congo, and Israel to India, more than a hundred scientists joined this ambitious effort to find some of the most elusive animals on Earth.

Here are some of their most spectacular discoveries.

These photos originally appeared in bioGraphic, a brand new online magazine featuring beautiful and surprising stories about nature and sustainability.